ChristianW

Most recent activity

• Help needed hacking a BLE TPMS

  @ChristianW started

  • 12 comments
  • 922 views

  @user126998 replied
• Raspberry Pi Pico

  @ChristianW started

  • 12 comments
  • 931 views

  @IrregularShed replied
• Raspberry Pi Pico

  in Porting to new Devices • 3 months

  

  Someone considering porting Espruino to Raspberry Pi Pico?
  https://www.raspberrypi.org/products/ras­pberry-pi-pico/

• TPMS - Tire Pressure Monitoring System

  @ChristianW started

  • 5 comments
  • 611 views

  @Gordon replied
• TPMS - Tire Pressure Monitoring System

  in Projects • 3 months, 1 week

  

  Update:
  After testing for a few weeks there were issues with the battery life. In the beginning sensors worked for days without noticeable battery wear.
  Then some other sensors started failing after only 1-2 days, eating batteries like candy.
  I bought another (identical) set and tested indoors with a modified aluminium water bottle and all was fine. Once the sensors were installed on the wheels some of them also started to drain battery.

  Taking the first set indoors again and counting messages showed that some sensors (the ones with the battery issues) sent far more messages than the others.
  I don't know if this is a hardware issue or if there is more about the protocol than I first thought.

  But how can they run dry when there is not a smartphone around? This is probably the case in 90% of the time...

  I just ordered a different/updated version (BLE 5.0) now and have a look at their protocol and battery lifetime. The outer caps just look similar. Stay tuned...

• Spare display for Pixl.js?

  in Puck.js, Pixl.js and MDBT42 • 4 months, 1 week

  

  Ah yes, @Gordon thanks for mentioning. But I feared to run short of GPIO pins in this future project... ;-)
  And for those who wonder (and asked) - there was an eBay link at the top of that thread already: https://www.ebay.co.uk/itm/122179960272 - looks like the baby version of the Pixl.js display.
  The display also has a backlight. It seems to be a bit "whiter" than the one of Pixl.js.
  And it runs on 3.3 V - the 5 V rating of the eBay listing probably only refers to the backlight (which runs off a GPIO pin as well in my case).

• Spare display for Pixl.js?

  @ChristianW started

  • 20 comments
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  @ChristianW replied
• Spare display for Pixl.js?

  in Puck.js, Pixl.js and MDBT42 • 4 months, 1 week

  

  Works. Just using the library I mean. Somehow I did not know where to look.
  Thank you very much!

  I even found the smaller displays I accidentally ordered before the ones used for the Pixl.js and connected them to the MDBT42Q.

  Looks cute, don't you think? ;-)

  Now I have a micro-Pixl.js...

• Spare display for Pixl.js?

  in Puck.js, Pixl.js and MDBT42 • 4 months, 1 week

  

  That's great! Nice of them to stick the connectors in too - that would have been super helpful when I was prototyping it!

  Look what I found on eBay. Those fit perfectly for the Pixl display.
  And since I have 3 spare ones from last year in my box.

  And by the way:
  How can I access the displays from the MDBT42Q breakout board?
  Unfortunately two of the "original" Pins used for Pixl.js are missing on the breakout board.

  Let's say I can solder them on - can I just flash a Pixl.js image onto a MDBT42Q?

• TPMS - Tire Pressure Monitoring System

  in Projects • 4 months, 2 weeks

  

  The sensor sits on the valve top. So it is mainly the outside temperature, not the gas temperature...
  I think it is more about compensation. If you change from a cool underground car park to hot summer roads the temperature rises and so should the pressure.
  If the pressure stays the same but the temperature rises this may be a leakage so the alarm goes off. Thats what seemed to be happening once during testing when I covered the sensor with my (warmer) fingers.