Differences

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--- hamradio:mmdvm:pog [2019/08/14 02:17] – philpem
+++ hamradio:mmdvm:pog [2019/09/05 23:23] – [MMDVM POG board mods and notes] philpem
@@ Line 1: / Line 1: @@
 ====== MMDVM POG board mods and notes ======
-The [[https://github.com/wojciechk8/MMDVM_pog/|MMDVM POG]] board is a widely-available Raspberry Pi HAT. It uses an STM32F105R8T6 microcontroller with a simple analogue front-end to connect a Raspberry Pi to a radio transceiver.
+The [[https://github.com/wojciechk8/MMDVM_pog/|MMDVM POG]] board is a widely-available Raspberry Pi HAT. It uses an STM32F105RBT6 microcontroller with a simple analogue front-end to connect a Raspberry Pi to a radio transceiver.
+**Warning** -- some MMDVM POG boards (especially the Chinese clones) are built in a Raspberry Pi HAT form-factor and have the 3.3V LDO regulator fitted. **The regulator must not be fitted if the board is being used as a HAT!**. Leaving the POG's LDO fitted may damage or destroy the power management IC on your Pi (this is especially common on the Pi 3)!  Remove the LDO regulator before using the HAT.
 ===== In-system re-flash =====
@@ Line 30: / Line 31: @@
 It should now be possible to upgrade the board's firmware using the tools included with Pi-Star.
+To flash manually:
+<code>
+stm32flash -v -w firmware.bin -g 0x0 -R -i 20,-21,21:-20,21 /dev/ttyAMA0
+# -v: verify writes
+# -w: write flash from file
+# -g: start execution at specified address (after loading)
+# -R: reset device at exit
+# -i: GPIO sequence --
+#       enter with GPIO20 high and toggle GPIO21 L->H
+#       exit with GPIO20 low and GPIO21 H
+# /dev/ttyAMA0: Pi serial port
+#
+# default baud rate is 57600
+</code>