Differences

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--- microcontrollers:pic [2022/01/23 19:10] – Embedded development on FreeBSD is easy ChristosMargiolis
+++ microcontrollers:pic [2022/01/23 22:55] (current) – Avoid unnecessary erase if chip is blank TrevorRoydhouse
@@ Line 17: / Line 17: @@
 ''%%/usr/local/share/sdcc%%''
-For programming the MCU, I've found ''%%pk2cmd%%'' to work alright with PICKit2,
+For programming the MCU, I've found ''%%pk2cmd%%'' to work well with the Microchip PICKit2 programmer (or Chinese clones),
-but there's no port for %%FreeBSD%% anymore. The Makefile won't install
+but there's no port for %%FreeBSD%% anymore. The Makefile won't install files properly, so we have some extra work to do afterwards:
-files properly, so we have some extra work to do afterwards:
 <code>
@@ Line 33: / Line 32: @@
 ===== Detecting and programming the MCU =====
+:!: AUTO-DETECT WARNING: Always select the device family BEFORE connecting the chip to limit the maximum VPP that the PICkit 2 applies to the chip. Otherwise you risk damaging the chip and spending an inordinate amount of time trying to resolve issues with what is now a damaged chip.
+To avoid damage to chips by VPP voltage levels above that rated for the chip the recommended method for auto detection is:
+) Get and cache a list of supported devices and families with
+-?P
+) Get and cache a list of auto detectable families and IDs with
+-PF
+) Use 1 and 2 to determine the family ID for a given part. Auto detect the chip using -PFn where n is the family ID.
+The //better option// is to avoid auto-detect altogether and specify the chip part number (eg PIC16F877A).
 Assuming you've wired the MCU and the programmer correctly, hook up
-the programmer to your computer and try to auto-detect the board. If
+the programmer to your computer and check the chip is blank. If not erase the chip.
-any of the following ''%%pk2cmd%%'' commands fail, make sure everything really is
+If any of the following ''%%pk2cmd%%'' commands fail, make sure everything really is
 wired properly:
 <code>
-$ pk2cmd -P
+$ pk2cmd -P PIC16F877A -C
-Auto-Detect: Found part PIC16F877A.
+Device is blank
 Operation Succeeded
 </code>
@@ Line 54: / Line 65: @@
 </code>
-Erase the PIC and flash the new code. Again, use the appropriate names:
+Erase the PIC (if the blank check failed) and flash the new code. Again, use the appropriate names:
 <code>
@@ Line 72: / Line 83: @@
 Operation Succeeded
 </code>
+----
+{{tag>HowTo}}