Comments: RETIRED - Load Cell Amplifier HX711 Breakout Hookup Guide
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Hello Sarah,
In the hardware hookup section regarding the Load Sensor Combinator, "The center tap or center pin of your strain gauge connects to the “W” pin on the combinator. The larger resistance wires (White and Blue in this example) connect to the “R” and “B” pins on the combinator." This configuration appears to be incorrect because the resulting circuit doesn't match what I'd expect for the wheatstone bridge using 4 load sensors. See this diagram of the expected wheatstone bridge circuit:
http://www.instructables.com/file/FUO46W0I0C96FJG/
If you connect the center-tap wire to the "W" of the combinator, then the combinator won't work correctly.
Thoughts?
The wire colors can vary between load sensors. We recommend measuring the resistance between wires. The two wires which have the greatest resistance should be connected to "W" and "B". The wire which has the least amount of resistance (when measured against the other two wires), will connect to "R".
Thanks Alex! Just to confirm my understanding, the wire with the least resistance is the center-tap, correct? If so, the hookup guide has a typo.
Thanks again!
Yes, the wire with the least resistance is the center-tap.
Yes, it does appear to be a typo.
Hello Sarah, The hookup guide specifies that the center-tap of a load sensor should be connected to the "W" of the combinator, but I'm not sure that's right. I would expect the center-tap to be "R". Thoughts?
It'd be nice to be able to upload a drawing of how this assertion changes the circuit diagram significantly.
It is like the diagram in this stack exchange answer -- essentially, the eight resistances in the 4 half-bridge load cells become two resistances per arm of the wheatstone bridge. The combinator tries to hook the center taps of the cells to the E+/E-/S+/S- of the HX711, and wires up the end-taps so that the 4 tension resistances are on opposite diagonals, and the 4 compression resistances are on the remaining diagonals. This way, the wheatstone bridge adds up loads on the cells, becoming more unbalanced as the increasing load increases the tensions (increasing their resistances) and increases the compressions (decreasing their resistances).
Hello Sarah,
I have the same setup as the previous poster A TAS606 (50kg) hooked up to an HX711 attached to an arduino uno. I can run the calibration sketch and adjust the calibration so the cell is reporting zero with no weight -- when I put a known weight (or any weight) on the cell, it does not register anything consistent on the serial monitor, but gives a series of wildly varying weights broken up by 20-30 "0 lbs" lines. I have tried calibrating from -20000 to +20000 to see if I am just out of the range but I cannot get my load cell to register anything consistently (positive or negative). I checked that all my wiring is correct, power is getting to the HX711 (4.8V) and to the load cell (4.5V), and a signal is coming back (~30-100mv from the Hx711 to the arduino both with and without a load), the arduino is just not displaying anything resembling a stable reading.
Help?
Thank you Brian
Sure, ok so the way the calibration code works is that upon boot up it registers that weight as 0 lbs, so when you run the code make sure nothing but your top panel is on the weight sensor, open up the serial interface and check that it is indeed 0 lbs as it should be, you do not need to adjust the calibration code for the 0 lbs it should be doing that automatically. Now after you have booted it up with what you will be calling 0 lbs and opened the serial communication, then put a known weight like 10 lbs on your top plate and adjust the calibration code to have it reflect that it is 10 lbs (or whatever weight you have on there). Remember that calibration number so that you can put it into the example code when you upload that to the arduino uno. I hope that helps, it just sounds to me like you were trying to calibrate for 0 lbs when it actually automatically does that when you start the code. Let me know if that changes anything or if you are still having issues. If that doesn't fix the problem we might have to consider the idea that the HX711 may not be working (I had this happen once in all of the testing I did), some signs that your HX711 may be broken is that it never outputs anything, so just be aware that that might be a thing, but hopefully not!
Hi Sarah, you mention a HX711 could be broken if it is not outputting anything. When I apply 5V to VCC and GND to GND on the HX711, I only get a short burst of 4.2V between E+ and E-. Do you think that my HX711 could be busted?
It might be, to make sure you should call/email customer service/tech support so that they can walk through if it is broken, and possibly get you a new one if it is.
303-284-0979
customerservice@sparkfun.com
I hope that helps!
Hi Sarah, Thanks for the quick reply. Your comment had me thinking that there may be an issue with the signal the arduino was getting as my unit wasn't always reporting zero when I first ran the sketch. I don't know if anyone else has had to do this but in my case the fix was to connect DAT ->digital 3 and CLK -> digital 2, which is swapped from the connection diagram on the hookup guide page. Once I did this things worked just as described -- I suppose I should have just looked closer at the calibration sketch, as these are defined at the top but they are different from the connection diagram. As an FYI my calibration ended up being -25000 for the 50 kg TAS606.
Thanks for your help, and a good reminder to read the code for me! Brian
You are correct! I have fixed the error, thank you for catching it, and I'm glad you figured out the issue and everything works now!
Hello,
I have 4 different load cell sensors and would like to connect two load cells to one HX711 board. Is it possible to communicate to each sensor separately through the one board? Meaning, would I be able to view the load cells' data separately, or does it only appear as one added weight? I hope my question is clear...if not I will try to clarify.
I connected a bathroom scale to a HX711 Load cell amplifier using a Load combinator board. I managed to find the center tap wire on the load cells in my scale and connected them to center W pins and connected the 8 other wires to the pins above and below them, with a single color (white) on one row of pins (R) and a single color (black) on another row of pins (B). As far as I know, I followed all the instructions. I have tried different example codes and different libraries, but I can't get the scale to read anything other than zero. Can anyone help me with this?
Thanks, Joran
Hi Jordan. It's not really intuitive on this board, but the terminals labeled R are for the center taps and W and B are for the outside legs. Try putting your center tap wires on R and see if the problems clear up. The reasoning behind this color scheme is it matches our load sensor. Your sensors might have different colored wires though.
Dammit... I spent like 20 minutes last night trying to figure out which was for the center taps, and I found this:
"To determine how to hook up your single strain gauge load cells to the combinator, measure the resistance between the three wires. You should find a larger resistance (close to double) between a pair. In our example the resistance between White and Blue was 1.8k Ω, and the resistance between White and Red was 900 Ω. Therefore, the center tap to the strain gauge is the Red wire. The center tap or center pin of your strain gauge connects to the “W” pin on the combinator. The larger resistance wires (White and Blue in this example) connect to the “R” and “B” pins on the combinator."
in the Hardware Hookup section: https://learn.sparkfun.com/tutorials/load-cell-amplifier-hx711-breakout-hookup-guide#hardware-hookup-
Did I read this wrong, or does it say the opposite from what you are telling me? Not that I don't believe you, but if this is wrong you might want to consider correcting it. I'll try swapping out the R and W pins for all load sensors after dinner and post the results then.
Thanks for the quick reply and assistance, glad I spent the extra dollar on the combinator board, can't imagine trying to troubleshoot the mess of wires I would have had if I had tried to build the wheatstone bridge myself.
That will cut the connection of the two, but then it will be very hard to close it again if you want to. So we suggest cutting in between the two silver pads, that way you could make a solder bridge between them if you ever want to close it again.
I hope that helps!
Hi,
I was just going to download and install the Sparkfun HX711 library from GitHub using the link in the tutorial. Downloading the zip file works fine, but when I try to install it either by manually copying it into the library folder or using the function within the Arduino IDE I get a error massage saying "It is not a valid library", i.e. the library cannot be installed. What do I do wrong? Thanks, Mathias.
Which library folder are you copying it to? The one in Documents/Arduino or the one in the Programs file?
The one in Documents/Arduino/libraries
Sometimes you get that response when there is - in the name, because Arduino can't take that. So if it is called library-master (because that is the way github formats the name) you will have to rename that file (and any files inside) library_master or something like that, that Arduino is ok with. Let me know if that helps.
Thank you, Sarah. Unfortunatly that did not worked. As a test I inserted the "SparkFun_ESP8266_AT_Arduino_Library-master" library w/o problems. Must be something else.
Hmmmm, well then, you got me. I think you should call into customer service and they will get you to a tech support person who can walk through and help you with your issues. I think that's your best bet, sorry it wasn't a quick fix =(
ok, thanks. will do.
Hello Sarah,
Sorry for asking again. Do you know how can I save my readng from hx711 load sensor to database (ex: mysql)? Thanks
Hello Sarah,
I am a noob in arduino. I am currently doing my project involving hx711 1kg load sensor. I have already set up my sensor. but the scale reading keep getting negative and do not start with 0. I tried to calibrate but there always been error on my code. I have adjusted the library hx711.h but error keep appearing. Can you help me?
Thanks
Hello Sarah,
Could you please help me, I have a 50 kg 3 wire Load Cell hooked up to an HX711 connected to gizduino atmega 1281. I have tried your code for getting the calibration factor but unfortunately the reading has always been 0. I placed a bottle of water weighing 1 kilo but I always get a reading of 0.
Please help me?
Thank you
Which colors are you hooking up to where on the HX711? A 3 wire is a load sensor not a load cell, so it doesn't have that wheatstone bridge in it, so it may be harder to read, which is why people usually hook 4 of them up with the combinator board and then the HX711. Your issue may be that it is much too small of a change to monitor with our code, or that the HX711 wants a wheatstone bridge hooked up to it.
The three-wire sensor is a half-bridge--essentially two of the variable resistances in a wheatstone. You could make the other half of the full wheatstone bridge with another half-bridge sensor, or with a variable resistor with its center tap set to match the voltage at the sensor's center tap.
Hi Sarah,
I am using a 1 kg load cell connected to a HX711 and then an arduino uno. I was wondering what changes I need to make to the code to output a value in grams? Also what sort of calibration factor should I use. I feel like the one provided is much too large.
Best, Ethan Mechanical Engineering Student
Hey Ethan, To get your calibration factor run this calibration code first, and put on a known weight, and change it until the output reads the actual weight.
As far as changing the value to grams, you would need to change the "lbs" to "kg" in the code (found here) where it says:
"Serial.print("Reading: ");
Serial.print(scale.get_units(), 1); //scale.get_units() returns a float
Serial.print(" lbs"); //You can change to kg but you'll need to change the calibration_factor"
But like it says, make sure that when you calibrated it if you used a 0.25 Kg weight, make sure it read out "0.25" (though the calibration will say lbs, but that is fine, that's just the name not linked to anything else). Hope that helps!
hey there i try to hook up my load cells and i have troubles with it . i have 4 load cells , a load cell combinator and the hx711 the first problem i have is that the weight change constantly without having anything on the load cell . i try to change the cable but is wasn't working . and the second problem i have is that the loadcell don't response at all to any weight . any idea why ????
This is a common problem that is hard to diaganose like this, I would recommend calling into customer service or tech support and having them walk through it with you. Otherwise you can read some of the other people's comments here and see if any of their tricks will work for you as well.
Customer service number: 303-284-0979 Email: customerservice@sparkfun.com
Sorry I couldn't be of more help.
Hello Sarah, i'm currently working on a project which starts with this. At the moment I am seeing only 0lbs on the calibration and the load sensors are not responding. A few questions,
Thank you for this. It is very helpful.
Hello, I have found that it does matter which is hooked up to B and R, so If you know for sure that the wire you have hooked up to W is the "center tap" then try switching the other wires. No the load sensor should work fine off of the Arduino power, the black and yellow wires you are seeing in that picture were to power a LCD screen since I hacked the scale to use it's load sensors. Along with the the load sensors, and the combinator board, make sure you have an HX711 amplifier board, because otherwise the output is too small for your Arduino to detect. I hope that helps! If you are still having issues, please feel free to call or email our customer service/tech support, so that they can help you in person, and walk you through any issues you may still be having!
No, the center tap should not go to 'W'. To turn the 8 resistances from the 4 three-wire sensors into 4 2-resistance legs of a wheatstone bridge per the combinator schematic the center taps should be on the 'R' terminals.
hi, I'm an Arduino noob so excuse my ignorance ahead of time. How to i connect the loose wires from the load cell to the hx711. I see how it's done in the tutorial but don't know what to call that piece, or pieces, that i need. It doesn't look like there's any soldering going on, unless I'm mistaken.
That's fine, of course! I did actually end up soldering wires to the HX711 but then just plugging into the RedBoard (or arduino). To make it easier for me I soldered jumper wires in, but that's a little more unusual. Unfortunatly you do have to solder to the HX711, since headers are not included on the board, if you have never soldered before we have tons of great tutorials on it (like this one on through hole soldering) and I would highly recommend taking a look at them. I hope that helped!
it did help. thanks. mine actually came with headers, so I guess I can solder the wires onto them. i'll give it a go, or get my son to.
I am trying to measure load and rotation on the same time. I have a load cell attached to the HX711. And I count pulses from a rotary encoder with interrupts on the Arduino. But functions work as expected when used individually, but not in combination. If I start the rotation while measuring load in the loop the Arduino hangs every time the puls frequency exceeds 10-20 Hz. Is it not possible to use HX711 in conjunction with interrupts?
Looking into the example code we posted for the HX711, they aren't any interrupts that would conflict with yours, so my gut is that should be able to, but I have not tested this, and again I don't know what your code looks like exactly, so yeah, I would definitely contact Tech support. Here is the direct tech support contact page for info, so you don't have to go through customer service first: https://www.sparkfun.com/technical_assistance
Thanks (you have great support). It seems that the problem occurs if the interrupt takes too long time, I had a test in the interrupt function that occasionally required a few extra calculations. When I removed them and just counted the pulses it seems to work. I will test further and contact support only if needed.
Cool, glad you're making progress. And thank you, we love your feedback and are here to help =)
Hmmm.. This is a tough one, I would need to see your code and what's going on more in depth, and since I can't do that here, I would advise you to either call or email our customer service/tech support, so that they can walk through this stuff with you.
303-284-0979
customerservice@sparkfun.com
Hopefully it is a simple fix, and they can work through it with you.
Hi, How do I connect 2 load sensors (50kg) to the combinator? Do I need 4 of those load sensors then only will it work?
You don't need the combinator. The load sensors are half-bridges and you'd hook the center taps directly to the S+/S- on the HX711. The end taps you would hook to the E+/E-, and depending on whether you want to add or difference the loads on the two sensors, you'd hook the end terminals up with opposite colors or matching colors. Opposite colors (black-to-white) will add loads, since increasing loads will pull one sensor(half of the wheatstone bridge) down while increasing load on the other sensor will pull that side up. If you match end-terminal colors with two 3-wire half bridges, then similar loads on each will move the sensor in the same direction.
The combinator helps wire the 8 resistances of 4 half bridges into a full wheatstone bridge with 2 resistances in each arm, trying to make sure loads on each half bridge add up constructively to to unbalance the bridge.
I would connect them next to each other, and then in the other two places put resistors. This will also act like a wheatstone bridge but just with two variable resistors instead of 4. Then hook that up to the amplifier board and test it with the code. It's going to be different, like probably slightly less accurate than using 4, but it should still work well with all the code. Hope that helps you!
I want to increase the data rate to 80 sps. To do that I am supposed to "open the jumper", but I am a little uncertain how do that in practice. Could someone guide me?
On the back, there is two little solder pads in brackets, with "rate" written under it, to "open the jumper" take a scalpel and just separate the connection which is part of the printed board. To "close the jumper" again just bridge the pads with solder. It's not very clear on the schematic, sorry. I hope that helps!
Thanks! I imagined it was something like that, but I didn't want to start cutting up the board based on a guess :)
Sure thing!
Where are you seeing that information? It doesn't look like this board has any jumpers.
Sorry, I was looking at the combinator. Listen to Sarah.
I am using a beam type load cell sensor for a fluid measuring station. I want to know the maximum downwards deflection of the load cell when load is applied on it. I tried searching it in the datasheet but couldn't find it. Can anyone please help me on this ?
Are you using one of our bar load cells? And if so can you link the page for it so I can try and help you? Thanks!
Hello Sarah, I am really sorry for the late reply. I am using this one - https://www.sparkfun.com/products/13329 Thanks!
No problem, this is going to be such a very small number, can I ask why you are looking for it? What application do you need to know that for? It might help me find the information better. I don't think they list this number since it is so small and hard to measure, and it might very well change from one specific load cell to the next. I'm hoping I can find it for you, but it may just be that they don't list it, and you would have to measure it yourself (which is extremely difficult).
We have a product in which we measure the amount of fluid on the tray. The tray is protruding out of a hole on a metal base.So basically the tray is connected to the load cell sensor through a acrylic stick through the hole present on the metal base. Now I need to maintain a minimum distance between the tray and the metal base so that load cell deflection is not blocked. If you have any doubts understanding this, let me know. thanks!
Interesting, I think I am picturing this right. The deflection is going to be very very very small, like not noticeable to the human eye, do you need more exact info than that? If so you will have to measure it yourself with some test weights, since the exact amount it deflects will depend on your specific cell and the temperature and some other various factors.
Thanks for the quick response. I think 5-6 mm gap should be fine. About the temperature effect, Does that really matter,shall I take precautions for that ?
If you can try to keep it at the same temp for more accurate readings, the load cell has compensated for the temp changes from -10 degrees C to 40 degrees C, so if you are within that range you should be fine to ignore temp. The load cells operating range is from -10 degrees C to 55 degrees C though, so if you happen to be operating between the temp of 40 degrees C and 55 degrees C the amount your readings might be off is about 0.05% per 10 degrees C, so still pretty small, but if that effects what you are looking for you might want to compensate for it with a temp sensor and some code adjustment.
I think I am within -10'C to 40'C only.So it should be fine. Thanks !
I have a little confusion about something. Between these two products Load Cell - 10kg, Straight Bar (TAL220) and Load Cell - 10kg, Wide Bar (TAL201) , other than the dimensions , are there any major difference ? Why would someone choose the wide one instead of the smaller one ?
Size is a big difference yes, but also the straight bar is made out of some additional materials which have slightly different qualities, like how it is effected by temp, and things like that. Since it is made out of both aluminum-alloy or alloy steel (the wide is just aluminum-alloy) it can also technically hold a bit more weight. I don't think for your purposes it will matter which one you choose, unless you have a space issue.
Choosing the smaller one would save me some space and cost also,so I will go with that. In the HX711 module, we normally don't use the 5th pin (Yellow) and B+,B- pins. What exactly are they for ?
Thanks again !
The yellow pin is for if you had a protective "ground" wire on your load cell, it is not essential and not overly common, so if you don't have one don't sweat it. The B- and B+ are pulled directly from the chip itself. They are used like the A- and A+ on the chip. I have never used the B- and B+ so they are just extras.
Thanks a lot. I think that's it from me for today :)
Hope you didn't mind answering bunch of stupid questions.
Nope, totally fine, they were important questions. I'm glad I could help you out with your project!
That's great. Can I ask some PCB design related questions here ? I am not getting any replies in the respective discussion place for the same.
I've only done a little bit of PCB design, so am a little less comfortable with that. You could try our customer service, but I'm not sure if they would be able to help with that specifically, but you could try and see. Sorry I can't be of more help.
It's alright. You have helped enough already.
Thanks
hello Sarah,
I have a small doubt. Is there any problem if load sensor comes in contact with water ?
If the sensor is powered at the time, there may be problems, and also depending on what was in the water (if it wasn't pure water) might mess with things even after it is fully dry.
hey sarah, Just one more question,There is a component called JUMPER-PAD-2-NC_BY_TRACE connected to the rate pin of HX711 IC on the sparkfun HX711 module for setting the data rate which is by default closed. Question-1 . In which application do I need to open it for setting the data rate to 80 SPS ? Question-2 If I am making my own HX711 module board and need the data rate to be only 10 SPS, Can I just short the rate pin to ground ?
On our breakout board it is set default closed, shorting the rate pin to ground, which puts it at a data rate of 10 SPS. So yes if you have your own, short the rate pin to ground to get the 10 SPS rate. The case you would want it open for 80 SPS is if you want crazy fast reading because things are happening faster than the 10 can see. But this also means that you will get additional noise in the readings if you are just looking at longer term changes. I hope that helps.
Yes of course it helps. My PCB designing was on hold for this info :p Thanks a lot !
Hello Sarah, I am doing project with HX711 connected to a single 4 wired load cell and Arduino UNO. The project work wonderfully with the code provided and for now I am trying to connect 4 load cells of the same type. How many Hx711 is needed for that or just a single Hx711 is sufficient for 4 load cells (4 wired)?
Thanks.
So since you can't use the load sensor combinator board (those are for four single load sensors with three wires each) I would go the route of getting four HX711 boards, hooking each load cell to a HX711 and then each one into your Arduino UNO. This way you can look at what is being applied to each load cell and in the code you can add those for your total weight. Since each load cell already has a wheatstone bridge configuration in it (that's why there is four wires) I wouldn't suggest trying to put them in an additional bridge configuration and just have one HX711, though I am sure there is a way that could work out, I just wouldn't do that personally. I hope that helps!
Hi Sarah, Thank for the reply. I also have been wondering if I could just use a junction box to connect those 4 load cell and then connect it to a single HX711. Would that work? I have already purchased the HX711 and just looking into others way while waiting for them. Thanks.
Hello. I am busy with a project and require 3 of the same load cells hooked up to 1 HX711. Have you come right with 1 HX711 for your 4 load cells?
Thanks
I'm not sure I understand what you are asking, could you be more specific?
I'm not entirely sure, I would need more specifics about the junction box to say anything. I haven't done it myself so I wouldn't really know. But you can always try and see.
Hi, I'm thinking of project to continuous measuring the weight of a LPG bottle for my BBQ. That means, once I place the load cells under the bottle, the time frame where I want to do measurements is half a year to almost one year. During that time frame I want to measure only a few times, e.g. once a week for the time the BBQ is in use. Here is my question: is it actually possible to have the load cells under continuous force/stress over such a long time frame? Does the board always do a calibration step, once its measuring something or can it use the last data (e.g. one week ago when a change happened on the load cell due to using the LPG gas)?
Great question. It will not keep self calibrating like before, it will only calibrate using the number you gave it once. But our CEO Nate is using our stuff for a very similar application but he is measuring our beehive outside over time, about once every minute. He did a nice little write-up about how he did that and you can look at it here. Some things to take into consideration with a permanent setup is accounting for things like temperature changes and what is known as "creep", this is where slowly over a long time the constant pressure changes the calibration of the weights. There are also a ton of other stuff that can effect readings, so first thing you have to decide is how accurate you want your project to be. After that, if you decide you want it super accurate you will have to get creative with the code and compensate for all of these things that can effect the readings. Sorry for the vagueness, I hope that helps you some. Take a look at Nate's project as he does account for a lot of things like temp and creep and such. Let me know how your project goes!
Hi, I am trying to set up the load cell and i'm not sure if there's something wrong with the circuitry or the code, but I keep getting a string of zeros even after putting weight on it. Sometimes the string of zeros fluctuate and goes to a negative value when there is no weight on the cell. What am I supposed to do?
Hey! I'm sorry you are having issues. Make sure that you are not calibrating it to 0 lbs, it does this automatically. So when you run the calibration code you are getting 0? What ranges are you putting in for your calibration code? This needs to be right to get the calibration number right to run the actual code. What weight are you using to calibrate. Hopefully it's a code issue and not a part issue, but even if that is the case, if you call our customer service they can get you another one.
Hey Sarah, I am running the calibration code from this link: https://github.com/sparkfun/HX711-Load-Cell-Amplifier The serial monitor does not display zero (sometimes even a negative value) when there's no weight on it. When I wiggle the wires attached to the amplifier, the values fluctuate. I'm wondering if it's an issue with the soldering. What do i do? thanks in advance!
I would definitely check your soldering work, really make sure you have good connections. Also check that the wires are correct using the diagram in the wiring tutorial, wire colors change, and I have on many occasions messed that up and it has a similar effect. If both of those don't work and you can't get any info when opening the serial port in Arduino to run the calibration stuff, I would call/email/chat with our customer service, they can run through it with you, and if all else fails get you sent a new part if yours does end up being defective. Good luck! I hope that helps!
My load sensor seems to be fluctuating and tempreture sensitve. When I blow air on it, it picks up readings. Is this normal and is there a way to avoid this? A fault perhaps?
Thanks in advance.
These types of things are pretty sensitive to temperature and humidity sadly. You could try encasing the board in a protective epoxy (non-conductive) to try to minimize this. Or you could set it up with a temp and humidity sensor and code in some variables that will counteract the effect, but that is much more complicated.
This load cell amplifier is made to be used with a full bridge, or 4 strain gauges in a wheatstone bridge you know, but lets say I wanted 1 strain gauge can I use 1 strain gauge and 3 resisters that are the same as that strain gauge??
Yes you can totally just use one load sensor and three resistors and still get the same effect. Using more load sensors just helps with accuracy and weight range, but if you are fine with the weight range of your sensor then resistors work well to help amplify the signal some. You will still probably want to use the amplifier board with it since it's still going to be a small enough signal and change that it is hard to read with a microcontroller. I hope that helps!
Hi, I would like to take this program further by display on software like processing and storing the data possible. I'm new to all this so would like to ask if there are any tutorials available.
Thanks in advance Hash
Awesome! Yeah we have a few that I can think of that might help you get started depending on what exactly you would like to do. Here is a tutorial where there is an explaination and some example code about storing info onto an attached microSD card (amount other things), and Here is a tutorial about OpenLog, which is a thing that stores data for later retrieval. I hope that's enough to get you started in the right direction! Let me know if you have any other questions!
Hello Sarah,
I have bought the Load Cell - 200kg(TAS606). Following the instructions of the hookup guide and using red and green as excitation and yellow and white as output, the example sketch is still reading 0 lbs regardless of weight. I would be very glad if you could help me.
Thanks, Ali
Hey Ali, Did you go through and set up the calibration code? You need this data to be able to put the right info into the example code. You can find the calibration code here. The code kind of explains how to run it, set it up, get a reading for 0 lbs, and then put a known weight of 10lbs and see that reading and then it will give you info to put into the example code. Let me know if that helps. Otherwise we can try some other things!
Just so you know if you would like to call our customer service they can get you to our technical support team who would be happy to help you with your project and try to troubleshoot with you. Our number is 303-284-0979, give us a call if you like.
Hello Sarah,
Thank you very much for your support. I went through the calibration code but the problem remains. The problem in my case is that the ouput is always "0 lbs" regardless of how much weight I am putting on the sensor. So I can not even calibrate the sensor because the output doesn't change. I measured the two output signals of the wheatstone bridge with a measurment device while putting weight on the sensor. The measurement device shows a change. Is it possible that the IC is defect? If yes, how can I check that?
Thanks, Ali
So you have the 200kg disc load cell between two boards (or something akin to that) hooked up with a amplifier board and to a micro controller? What kind of micro controller are you using, RedBoard? Arduino Uno? Pro Mini? Just trying to get more info to try and find the problem. Are you thinking that the amplifier board is defective? We can try to test a few things but I personally don't know how to test that it is working, though if you suspect it isn't, you can call customer service and they can look into sending you another. Sorry you are having issues!
The disc load cell is standing freely on my desk. It is connected via the amplifier board to an Arduino Uno. Through pressing a plate on the load cell I'm applying force on it. I also checked the soldering connections to the pin header on the amplifier board, which are ok. I would be happy if you could give me a hint for the solution. I am writing these from Germany. Preferably I would ask the customer service in writing if possible. Is there a special email address for that or is education@sparkfun.com correct?
You can email customerservice@sparkfun.com, that is a better way to reach people who can help you right away.
I have an application where I need to measure both compression and tension: push and pull.
Is it possible to configure a bar cell to measure tension? Perhaps using a variation of the two plates Z configuration shown in this tutorial?
If so, can I measure both compression and tension with the same bar cell or would I need two cells and two amplifiers?
Thx. Don.
Hey Don, Great questions, the bar load cell in the Z formation is technically measuring both tension and compression (two strain gauges are in tension, two in compression when weight is applied to the top plate), this means that yes if you then wanted to measure tension being applied to the top plate the opposite strain gauges on the load ell would be in tension vs compression. So you would only need one load cell and one amplifier set up in the same Z formation. Now as far as the code goes (the calibration code), you might get some interesting numbers since that is not what it is meant for , I have not tested that and you may need to modify the code to include a number to calibrate a known value of tension as well. I'm not 100% sure on that as I have not tested it specifically. Let me know if you try it and how it works out, but mechanically it will work the way you want.
Sarah
Thanks for this, I will order some to play with and let you know the results.
Don.