New blog post: Designing a standalone ATmega328 board
For the AWA RT85 CTCSS circuit
https://circuitstate.com/wp-content/uploads/2023/01/ATmega328P-28-DIP-Pinout-Diagram-Rev-0.5-CIRCUITSTATE-Electronics-1_1.png
VCC and AVCC to 5V
AVCC for analog measurement
Don’t connect AREF! https://forum.arduino.cc/t/what-is-avcc-for-on-the-atmega328/66423/6
5V available from P903 (pin 1), and […]
https://blog.narf.ssji.net/2024/05/07/designing-a-standalone-atmega328-board/
New blog post: Random discoveries
Olimex now has the ESP32-POE2 https://www.olimex.com/Products/IoT/ESP32/ESP32-POE2/open-source-hardware, which has a nice configurable 12/24V line that would make it substantially easier to build my water tank sensor. Waiting for Mouser to carry it.
I finally settled for EH connectors for the CTCSS module for my AWA RT85. They were surprisingly hard to find. I […]
New blog post: The quest for the correct connector (cont’d)
The AWA RT85 manual has an error (see The quest for the correct connector). The CTCSS module needs to connect to J903, not J901
It’s an EMCS-0851ML
Handy site to OCR screenshots: http://www.structurise.com/screenshot-ocr/
Can’t find EMCSes anywhere. I think I’m going to replace them by brand new JST EH connectors
https://blog.narf.ssji.net/2024/04/01/the-quest-for-the-correct-connector-contd/
New blog post: The quest for the correct connector
Need to find a connector that actually connects to the AWA RT85.
M20 headers with a 2.54mm pitch fit, but I don’t get contact
Asked for help on Mastodon https://piaille.fr/@shtrom/112068949230147198
JST was mentionned… But which one? Maybe EH? https://www.mattmillman.com/info/crimpconnectors/common-jst-connector-types/#eh […]
https://blog.narf.ssji.net/2024/04/01/the-quest-for-the-correct-connector/
New blog post: 141.3!
Continuing to work on a CTCSS generator for my AWA RT85
Disconnected the original 91.5Hz generator, and fed the output of my 141.3Hz test circuit via a 150kΩ resistor, as described in the radio’s manual
It worked! I can trigger a local repeater, hear myself on another radio, and also detecet the 141.3 when tone-scanning. All […]
New blog post: Adding CTCSS tones with an Arduino
Need to add tones to the AWA RT85
http://www.pa3guo.com/PA3GUO_Arduino_CTCSS_v1.2.pdf use PWM with varying duty cycle into a bandpass to generate the desired tone
Arduino/ATMEGA https://github.com/tczerwonka/arduino-ctcss
No 91.5 in RT85 programming map, map to 0/no-tone?
WIA default standard tones […]
https://blog.narf.ssji.net/2024/02/07/adding-ctcss-toness-arduino/
New blog post: Adding CTCSS tones with an Arduino
Need to add tones to the AWA RT85
http://www.pa3guo.com/PA3GUO_Arduino_CTCSS_v1.2.pdf use PWM with varying duty cycle into a bandpass to generate the desired tone
Arduino/ATMEGA https://github.com/tczerwonka/arduino-ctcss
No 91.5 in RT85 programming map, map to 0/no-tone?
WIA default standard tones […]
https://blog.narf.ssji.net/2024/02/07/adding-ctcss-toness-arduino/
New blog post: Updating scan list
I want to close my AWA RT85 with some progress
Haven’t worked out the CTCSS module or frequency encoding yet
I can change the scan list to local repeaters
Got the updated repeater list from the WIA
Played with VLOOKUP in LibreOffice
Also, conditional formatting, but had to file a bug
Also copying the 2m FM call freq to […]
New blog post: Off-by-one
Found an annotated list programming guide for the 2m AWA RT85 by VK2KJF: http://www.unixsupport.com.au/hamradio/radios/awa/rt85/RT85_Manuals/AWA_RT85_programming-part4.pdf
Realised I had an off-by-one error between the frequencies and the dumped codes in the EEPROM
Which means I was wrong about where channel 0 is. Channel 0 is… at index […]
New blog post: Some visual inspection and doc reading
Some clues while looking at my AWA RT85:
A label on the underside mentioning it has a 91.5Hz CTCSS encoder fitted
Looking at the receiver circuit where the official Z-281 CTCSS encoder circuit is supposed to be… it’s not
but there is a circuit connected to P358.
need to work out if it’s controlled by the EPROM, but I […]
https://blog.narf.ssji.net/2024/01/06/some-visual-inspection-and-doc-reading/
Olivier Mehani