1/30/2021 - bringing up boards notes

• Sch/brd name Wedding 5
• Using Atmega328PB
• AAA battery footprint (not AA as mentioned before) still not quite right
• Programming over ISP works, power supply works
• Programming over FTDI/ UART works, I found this to be finicky, see next log for details
• Blinktest.ino works with all LEDs
• LEDs have 124 ohm resistors, could probably go to 150 ohm
• CS has a 10k pullup
• Trick: open -n -a EAGLE in terminal to see more than one instance
• TODO: 
  • test internal oscillator (8 MHz)
  • test cap touch sensor

Testing radios today:

Name/ Port/ Atmega pin/ Arduino IDE pin

• CS / PB2/ 14/ 10
• SDO (MOSI0)/ PB3 / 15/ 11
• SDIO (MISO0)/ PB4 / 16/ 12
• SCK0/ PB5/ 17 / 13
• RADIO RESET/ E1/ 6/ 24
• INT/ PD2/ 32/ 2 

BATTERY LIFE

• ADC, 10 BITS, GND REF, 0 - VCC RANGE
• ADC HAS SEPARATE POWER SUPPLY AVCC. 
  • AVCC must not differ more than ±0.3V from VCC. 
  • Needs capacitor added to pad (oops)
• BATTERY READ/ ADC6/E2/ 19/ A6
• V(out) = V(in)*(R2/(R1+R2)) where max Vin is 1.5 V (AAA battery), Vout is 1 V

• pin voltage mV = (ADC value *system voltage mV) / max ADC value //  1 V = (ADC value * 3.3V)/ 1024 // Max ADC = 310

PINOUTS

//    digitalWrite(0)         //--> D0
//    digitalWrite(1)         //--> D1
//    digitalWrite(2)         //--> D2
//    digitalWrite(3,LOW);    //--> D3
//    digitalWrite(4,LOW);    //--> D4
//    digitalWrite(5,LOW);    //--> D5
//    digitalWrite(6,LOW);    //--> D6
//    digitalWrite(7,LOW);    //--> D7
//    digitalWrite(8,HIGH);   //--> B0 
//    digitalWrite(9,HIGH);   //--> B1
//    digitalWrite(10,HIGH);  //--> B2 SSO
//    digitalWrite(11,HIGH);  //--> B3 MOSI
//    digitalWrite(12,HIGH);  //--> B4 MISO
//    digitalWrite(13,HIGH);  //--> B5 SCK
//    digitalWrite(14,LOW);   //--> C0
//    digitalWrite(15,LOW);   //--> C1
//    digitalWrite(16,LOW);   //--> C2 
//    digitalWrite(17,LOW);   //--> C3
//    digitalWrite(18,LOW);   //--> XX
//    digitalWrite(19,LOW);   //--> XX
//    digitalWrite(20,LOW);   //--> XX
//    digitalWrite(21,LOW);   //--> XX
//    digitalWrite(22,LOW);   //--> XX
//    digitalWrite(23,LOW);   //--> E0
//    digitalWrite(24,LOW);   //--> E1
//    pinMode(A2, INPUT_PULLUP); //-->25 (ALSO C2)

****************************

I received new PCBs early December, getting around to populating and bringing them up now. Here are the notes:

1. SDO/ SDI routed incorrectly everywhere, reversed on the radio and reversed on the programming connector.

2. LEDs are BRIGHT with a 100 ohm resistor. Maybe we'll go with less bright? TBD.

R13 & 14 are 100 ohm, the rest are 124 ohm

3.  AA battery holder is bigger than the footprint was designed for. The oscillator and the on/off switch interfere. Not a show stopper here, but should be fixed for the next rev.

4. For battery life, we're using a AA 1.5V battery. There's a voltage divider measuring the battery which gives an input to pin 19: ADC6/ E2. 

V(out) = V(in)*(R2/(R1+R2))