kesyog / hangman

A Bluetooth-enabled strength testing and training tool that scales
https://kesyog.github.io/hangman/
Apache License 2.0
17 stars 0 forks source link

Documentation tracking #4

Open kesyog opened 1 year ago

kesyog commented 1 year ago
cicatrix87 commented 9 months ago

Are you still working on a documentation? I would like to build some of those devices for a few friends, but how its now im a bit confused what and how to do it.

kesyog commented 9 months ago

Hey, I wasn't planning on writing step-by-step detailed instructions for building these. The process is a bit involved, especially if you don't have soldering and embedded experience and equipment. Also, I'd rather steer people toward getting a Tindeq to support their product.

I am planning on writing a high-level guide to document the project further and steer people around some of the obstacles I ran into. It'll live in the attached page, https://kesyog.github.io/hangman. Unfortunately, it's hard to find the time and energy to do this sort of thing so I probably won't get around to it for a while (likely on the order of months at least).

That said, if you do have the background, curiosity, and time to fill in the gaps, the quick summary:

  1. Buy this crane scale: https://www.amazon.com/dp/B07MTFXSJW
  2. Order the PCB's and electronic parts. I can dig up a parts list if you're interested.
  3. Assemble the PCB, ideally with SMT soldering equipment.
  4. Replace the existing PCB in the crane scale with your PCB and solder the load cell and battery wires to the PCB.
  5. Flash the s113 NRF SoftDevice image using nrfjprog --family nrf52 --program <path to hex file> --chiperase --verify. I used a Segger J-Link for flashing.
  6. Install Rust
  7. Build and flash the image. The repo is set up such that cargo run will build the image and use probe-rs to flash the image.
  8. Perform two-point calibration over BLE: https://kesyog.github.io/hangman/calibration.html
  9. Enjoy.

Hope that helps!

cicatrix87 commented 9 months ago

I already have a similiar crane scale that could work, in the end those load cells should work identical or? I will check if the originial PCB in this one has the same dimensions and screw points as yours. A Parts List would be highly recommended so a BOM&CPL that i could order everything together with the PCB. Sure i could buy a Tindeq but its more fun like this,

kesyog commented 9 months ago

It'll almost certainly work with a different load cell as essentially all load cell circuitry works the same way. Most cheap ones have the same 4-wire connection. Some more expensive ones have an additional two sense wires and/or an extra shield line, especially if they have a long cable, but shield can be tied to ground and IIRC the sense lines can either be ignored or tied to the corresponding +/- output lines.

Some things to look out for if you're using a different load cell:

Also, you'll need a known weight to do calibration, so it's helpful to have an unmodified crane scale (or any kind of scale) to measure your calibration weight.

Here's the part list I used:

Part Ref des Part number/Digikey part number Notes
SWD connector 1849-PM20B05VBDN-ND
Fanstel BT module BT832 https://www.fanstel.com/bt832-1-1
Push-button 2223-TS02-66-70-BK-160-LCR-D-ND
TI ADC ADS1230 https://www.digikey.com/en/products/detail/texas-instruments/ADS1230IPWR/1689136
PFET Q1 SSM3J378RLFCT-ND
32.768kHz crystal SC32S-7PF20PPM https://www.digikey.com/en/products/detail/seiko-instruments/SC32S-7PF20PPM/4931504
RLED R8 RMCF0805JT100RCT-ND (for debugging)
LED 3147-B1911USD-20D000114U1930CT-ND (for debugging)
10pF C1 C2 1276-1069-1-ND
0.1uF filter caps C6 490-GRMJN65C1H104JE01JCT-ND https://www.digikey.com/en/products/detail/murata-electronics/GRMJN65C1H104JE01J/19115572
10nF filter caps C3 C7 490-GRT1885C1E103JA02JCT-ND
0.1uF C4 C5 1276-1935-1-ND
10uF C8 C9 C10 1276-2399-1-ND
47 R4 R5 R6 R7 RMCF0603FT47R5CT-ND
100 R1 R2 RMCF0603FT100RCT-ND
49.9k R3 R9 RMCF0603FT49K9CT-ND

Let me know if/when you get it working. I won't be able to give too much debugging help, but I might be able to point you to relevant docs I found helpful.

roviraleix commented 5 months ago

Hello,

any updates on it? I've got an nRF52840 board and a HX711 and would like to try to make it work with the tindeq app. Just adding this 2 components to the crane and leaving the original board. I was wondering if it would be possible to flash the nRF with the tindeq firmware.

Regards and congrats for this nice project!