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--- packet:ninotnc [2026/02/08 14:31] – [Experimental new modes] m0lte
+++ packet:ninotnc [2026/02/08 14:36] (current) – [Firmware] m0lte
@@ Line 324: / Line 324: @@
 * Note - for a startup script you should always use the temporary value rather than writing to memory each time
-=== GPIO ===
-With Raspberry Pi GPIO, put /usr/bin in the crontab path, and add the following to /etc/crontab:
-<code>
-# 1000 - BPSK300
-*     * * *   root    raspi-gpio set 5 op dh && raspi-gpio set 6 op dl && raspi-gpio set 13 op dl && raspi-gpio set 19 op dl
-# 1001 - QPSK600
-*    * * *   root    raspi-gpio set 5 op dh && raspi-gpio set 6 op dl && raspi-gpio set 13 op dl && raspi-gpio set 19 op dh
-</code>
-dl = drive low, dh = drive high.
-Wire the numbered GPIO pins to the bottom of the MODE DIP switch, turn all the switches off, and it'll mode-switch automatically. I've gone for BPSK300 for the first half of each hour, and QPSK600 for the second half.
-I picked GPIOs 5, 6, 13 and 19 (consecutive physical pins) to map to the DIP switch pins from left to right as you look at the PCB.
-=== MCP2221A ===
-The MCP2221A USB chip has four GPIOs which can be used to control the mode, instead of the DIP switches. This can be useful particularly on a remote site, and removes the need for a second cable (and works with a machine without its own GPIO interface).
-This is experimental and is likely to change. See https://github.com/g5dsg/2221aTool for up to date info. Thanks to Dan for working on this.
-General steps:
-''git clone https://github.com/g5dsg/2221aTool.git''
-Install python3.
-then, once (persistent):
-''sudo python3 ./2221aTool.py setup-gpio''
-this will configure the GPIO pins as outputs, and make them all low at power on.
-then, when required (non-persistent):
-''sudo python3 ./2221aTool.py set-gpio 1111''
-where 1111 is the state of the four switches, left to right.
-Wiring as follows. **NOTE - you MUST either remove the DIP switch or leave all four switches set permanently off with the jumpers in place.**
-Note: bit of an edge case, but it is required to run ''sudo python3 ./2221aTool.py setup-gpio'' at least once on a TNC before it can be flashed with new firmware, or indeed just used normally at all, at least while some of the MODE DIP switches are set to zero.
-{{:packet:ninotnc-mcp2221a-mode.jpg?400|}}
 ===== Pinout =====
-Note: this is the BACK / SOLDER side of the PLUG.
+Note: this is the BACK / SOLDER side of the PLUG. You are looking at the solder cups, NOT the pins.
 {{:kantronicstncwiring.png|}}
@@ Line 406: / Line 361: @@
 </code>
-Use v3 firmware unless you know you have a 512kb chip, which is none of the OARC UK kits (i.e. ignore the v4 firmware - it's the same, but for the bigger chip).
+Use v3 firmware if you have a 256kb chip, or the v4 firmware if you have a 512kb chip. They are functionally identical, just tailored for the memory map of the device.
 If you get dire warnings about bricked TNCs, know is this highly unlikely. Unplug TNC, reboot system, plug TNC, try again.