SparkFun Electronics Comments

LightningHawk on SEN-13261 - SparkFun OpenScale

2017-06-13T12:07:07-06:00

Here’s the kitchen scale I used.

Customer #1019680 on SEN-13261 - SparkFun OpenScale

2017-06-12T13:43:03-06:00

For the kitchen scale, is there any amazon link you can share that is easy to tear open and use? The user guide doesnt provide any particular kitchen scale compatible with the the 10kG load cell.

Customer #123207 on SEN-13261 - SparkFun OpenScale

2017-06-12T08:35:52-06:00

I have seen similar “jitter” in my readings; big jumps for brief periods of time. I’m assuming it’s a noise issue with ADC not helped by my un-shielded wiring. I also believe some the erroneous values are made worse by possible overflow/underflow in the averaging routine in the HX711 library. One thing that helped me was to modify the firmware to read (10) raw samples, scale them individually before summing/averaging, discard the lowest and highest individual readings, and then summing and averaging the remaining (8) scaled samples (see rudimentary code below):

long i, j, min, max; long rawReading[10];

//----------------------------------------------
// Take 10 readings w/ scale factor
j=0;
for(i=0;i<10;i++)
{
  rawReading[i] = scale.read(); // Take a single reading from the ADC
  rawReading[i] /= 8870;        // Scaling (hard-coded scale factor)
}

//----------------------------------------------
// Find lowest and highest reading
min=9999;
max=0;
for(i=0;i<10;i++)
{
  if(rawReading[i] > max)
    max = rawReading[i];
  if(rawReading[i] < min)
    min = rawReading[i];
}

//----------------------------------------------
// Sum and remove lowest and highest and average readings
for(i=0;i<10;i++)
  j += rawReading[i];
j -= min;    
j -= max;    
j/=8;   // Final value

Ramza on SEN-13261 - SparkFun OpenScale

2017-05-31T17:03:39-06:00

You can simply comment this out in the Openscale code. Look for setting_tare_point = (long)8647409; add // to comment it out

Ramza on SEN-13261 - SparkFun OpenScale

2017-05-31T17:00:13-06:00

Yes, I was able to do this. I used an arduino uno and I connected the Serial out of the Openscale to the arduino. So GND <-> GND, and the TX of Openscale to RX of Arduino.

For your code, just do the regular Serial setup for 9600 baud, and do Serial reads for the data.

Customer #1002333 on SEN-13261 - SparkFun OpenScale

2017-05-24T11:49:13-06:00

Has anyone tried to re-use the Temp signal as a GPIO? Theoretically you should be able to, but I was just curious if anyone has?

Customer #918806 on SEN-13261 - SparkFun OpenScale

2017-03-31T08:37:59-06:00

My OpenScale SEN-13261 has been reading undisturbed since about 5:20 pm yesterday with a 100 lb load; however, I’m occasionally getting outlier readings (+/- ~2700 lbs). Refer to the plots below; Is this noise from the HX711 ADC, or a firmware bug? Plotted values are the max/avg/min of the last 50 readings from OpenScale serial port.

load cell #1 plot:
load_cell_1
(on board) temperature #1 plot:
temperature_1

Steps I’ve taken to resolve the issue:
* Increase the time between OpenScale readings from 100 ms to 150 ms
* Flash the latest firmware from Github to OpenScale
* Re-read OpenScale documentation & search google

Any ideas on what to do about the outliers?
Is anyone else seeing this same issue?

Thanks in advance!

Customer #365903 on SEN-13261 - SparkFun OpenScale

2017-03-30T09:47:16-06:00

At 5v input required, how does one get this to run outside on a single 3.7v cell with Sunny Buddy? Seems strange that this was (as I understand it) initially designed to measure a beehive weight in an outdoor project, but then relies on 5v and has no wifi/ESP8266 option or terminal.

Customer #903845 on SEN-13261 - SparkFun OpenScale

2017-02-14T10:00:54-07:00

Hi,

I want to

Battery power this from a 5v regulated source
take the output from the serial out connections (i will send over BLE)

when i try to power this using 5v it works but does not start to send data on power, it just idles unless i connect via usb to the ftdi chip.

how do i make it start sending readings without connecting it to a usb port?

regards,

james.

Customer #650726 on SEN-13261 - SparkFun OpenScale

2016-12-30T11:21:10-07:00

Hello, Is possible to connect it to arduino? i’m using a xbee on arduino to send some data.

Customer #790198 on SEN-13261 - SparkFun OpenScale

2016-11-24T15:31:20-07:00

Can you interface wit this on i2c or SPI? I’m imagining setting up a screen for weight readout, but perhaps I should go with my own arduino and the HX711 load cell amplifier if I want to create a standalone device?

LightningHawk on SEN-13261 - SparkFun OpenScale

2016-11-17T10:17:52-07:00

The Atmega328 on Openscale is there to handle communication. There is no I/O broken out for something like blinking an LED or reading potentiometer output. However, I think you might be able to record and process data from the load cells in Labview. Labview does give you access to I2C and SPI functionality on the MCU-the SPI pins are accessible on OpenScale through the AVR programming header and SDA and SCL can be accessed from the drains of Q1 and Q2 - This will give you the Temp data. I haven’t used OpenScale with Labview but I might try now. I don’t see how it could be a greater benefit to use Labview in this case but I don’t see why it wouldn’t be possible. If resolution is what you are looking for though the Atmel MCU used on OpenScale is the same as the chip used on an Arduino so the resolution should be the same.

Customer #836772 on SEN-13261 - SparkFun OpenScale

2016-11-17T09:45:59-07:00

Is there a way to read the OpenScale in Labview? I just downloaded makerhub and have been experimenting with Arduino connected into LabView. I’m playing with an example which needs more resolution then a standard Arduino, can I plug my OpenScale into the program and record a potentiometer output using it?

LightningHawk on SEN-13261 - SparkFun OpenScale

2016-11-07T10:21:29-07:00

Hi, Thanks for bringing this to our attention. It has been updated.

frada on SEN-13261 - SparkFun OpenScale

2016-11-07T07:34:48-07:00

Hi,

opening the Eagle files available for OpenScale I see that probably they are related to a previous revision of the schematic/pcb because the combinor for individual load sensors is not present.

Is there any chance to have the Eagle files updated to the current release of the PCB?

Thank you for your answer.

Regards

Customer #836709 on SEN-13261 - SparkFun OpenScale

2016-09-13T11:37:13-06:00

In the latest firmware the loadcell tare value is not taken from EEPROM, its hardcoded to 8647409. is it a bug?

LightningHawk on SEN-13261 - SparkFun OpenScale

2016-08-22T09:53:36-06:00

Yes. You’ll need to re-calibrate once every season (at least) to take into account changes in temperature and humidity in the environment. Creep is the change in load cell signal occurring with time while under constant load and with all environmental conditions and other variables also remaining constant. Load cells tend to creep meaning they will change their output slightly over time when a weight is left on the scale for long (30+ minutes) periods of time. Creep is load cell specific so keep your data sheet handy and perform some tests. There’s an example calibration in the hook-up guide. If you need more info, I found this helpful: http://www.scalemanufacturers.org/pdf/loadcellapplicationtestguidelineapril2010.pdf

Customer #836709 on SEN-13261 - SparkFun OpenScale

2016-08-22T04:35:53-06:00

What is the meaning of “A load cell with OpenScale can remain in place for months without needing user interaction”, does it mean OpenScale needs calibration after using it for some months?

Customer #834586 on SEN-13261 - SparkFun OpenScale

2016-08-20T03:47:12-06:00

I have a bathroom scale with four load sensors, each sensor has four wires (not three). How do you suggest I connect it to the Openscale please? I can’t see any reference to four wire sensors in the hookup guide. Thank you.

Customer #727973 on SEN-13261 - SparkFun OpenScale

2016-08-06T12:29:19-06:00

In the Hookup Guide", the link to “the text configuration menu” is broken…

Customer #727973 on SEN-13261 - SparkFun OpenScale

2016-08-06T11:41:46-06:00

I found : the colors from the cell are not the same as the openscale ! It seems it works ! Thank for the reply !

LightningHawk on SEN-13261 - SparkFun OpenScale

2016-08-05T11:58:15-06:00

“No Remote Sensor Found” refers to an external temp sensor that is connected to the screw terminals on the board. I’ve never used that load cell before and I couldn’t help much with mounting it. I’m sure you can some documentation on mounting the load cell. Have you been in the calibration menu yet?

Customer #727973 on SEN-13261 - SparkFun OpenScale

2016-08-05T11:44:46-06:00

Dear sir, I am trying to use openscale with :

http://www.aliexpress.com/item/2PCS-lot-100KG-150kg-electronic-platform-scale-load-cell-pressure-balanced-cantilever-load-weight-sensor/1649112894.html?spm=2114.13010608.0.56.zVLOrD

I get : “No remote sensor found” Could it be a problem with the cells or which mistake can I make ? Yours faithfully Pierre

ksteddom on SEN-13261 - SparkFun OpenScale

2016-07-22T07:34:00-06:00

The link to the hookup guide is MIA.

Customer #472537 on SEN-13261 - SparkFun OpenScale

2016-07-22T06:23:07-06:00

Question: The ability to capture data, coupled with sending that data, via blue - tooth module, or wifi, with a potential AWS backend?

Thanks!