GeekBot

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• AT module and RN2483: not working with my Linux box

  @GeekBot started

  • 64 comments
  • 18,387 views

  @OwenBrotherwood replied
• SPI NSS Pin is set too early on send

  @GeekBot started

  • 5 comments
  • 2,866 views

  @Gordon replied
• SPI NSS Pin is set too early on send

  in General • 8 years

  

  I use a Saleae logic analyzer. You can purchase one on their website.
  It works great.
  GeekBot

• SPI NSS Pin is set too early on send

  in General • 8 years

  

  Hello,

  I try to connect a radio module using an SPI link (on SPI3, Espruino Pico, Firmware V1.90)
  Here is my code :

  SPI3.setup({sck:B3, miso:B4, mosi:B5, baud:10000, mode:0, order:'msb'});
  var registreW = {data : 0x81, count : 1};
  var modeASK = {data : 0x23, count : 1};
  var returnedData;
  returnedData = SPI3.send(registreW,A7);
  console.log(returnedData[0]);
  returnedData = SPI3.send(modeASK,A7);
  console.log(returnedData[0]);
  

  NSS Pin is A7.
  Since this code doesn't work (communication doesn't work), I had a look at signals with the logic state analyzer.
  I attach a screen capture. In fact, NSS PIN is set high too early, when the last byte is not totally sent. I looked at the code line 212, the PIN change seems to be executed without knowledge of end of transmission, but I can be wrong !!
  Help will be greatly appreciated.
  Best regards
  GeekBot

• Powering Pico with a 3V lithium battery

  in General • 8 years, 2 months

  

  I did some more measurements.
  Battery voltage 2.78V
  3.3 V output : 2.5V
  LED1 turned on, Espruino running.
  I confirm that the transistor has just some mV of voltage drop.
  Since, I estimate the current over 35 mA, I have to look at the regulator datasheet to see if it is an expected value.
  Anyway, I manage with these figures!
  GeekBot

• Powering Pico with a 3V lithium battery

  @GeekBot started

  • 12 comments
  • 4,948 views

  @GeekBot replied
• Powering Pico with a 3V lithium battery

  in General • 8 years, 3 months

  

  @Gordon, thank you, I will do accurate measurements and reporting tomorrow. I come back to you.
  Best regards
  GeekBot

• Powering Pico with a 3V lithium battery

  in General • 8 years, 3 months

  

  Thank you Gordon. So I connected on BAT_IN as you suggest, it's clearly much safer and easier to manage with USB connection. The voltage drop is about 0.3 V. That's 10% of the battery voltage, but acceptable for my application. I guess this drop comes from the MOS transistor?
  Best regards
  GeekBot

• Program doesn't execute the same after save() in flash

  @GeekBot started

  • 11 comments
  • 3,813 views

  @Gordon replied
• Powering Pico with a 3V lithium battery

  in General • 8 years, 3 months

  

  @Gordon, eventually I have a doubt; the 'Bat' pin you talk about is the 'VBat' pin (PIN2 of J2 on Pico, called 5V on the schematic) ?
  Because there is also the VBAT on the schematic which is the PIN 1 on J1, and called BAT_IN on the Pico coloured diagram on the web site.
  According to our discussion, I guess the 'Bat' is the 5V on the schematics, but I need to be absolutely sure.
  Thanks a lot
  GeekBot