Adafruit_ImageReader
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20 hours ago •
adafruit
adafruit
SPI clock comment for M0
This is only a comment addition to help troubleshooting. Modern chips are fine with 25 MHz SPI clock, but the older M0 needs 12 MHz or less with the FeatherWings TFTs microSD cards.
+---------------------+--------+--------+--------+
| Chip | 25 MHz | 12 MHz | 8 MHz |
+---------------------+--------+--------+--------+
| Feather M0 WINC1500 | x | o | o |
| Feather ESP32 V2 | o | o | o |
| Feather M0 Express | x | o | o |
+---------------------+--------+--------+--------+
Changing the default example clock from 25 --> 12 helped resolve a forum issue with the Feather M0 <--> FeatherWing 3.5" HX8357.
Most of the breakouts use 10 MHz for wire length accomidation.
+-----------------------------------+---------------------+
| Directory | SPI Frequency (MHz) |
+-----------------------------------+---------------------+
| FeatherWingST7735 | 25 |
| FeatherWingILI9341 | 25 |
| FeatherWingHX8357 | 25 |
| ShieldST7735 | 25 |
| ShieldILI9341 | 25 |
| PyPortal | 25 |
| BreakoutST7735-160x80 | 10 |
| BreakoutST7789-170x320 | 10 |
| BreakoutST7735-128x128 | 10 |
| BreakoutST7789-172x320 | 10 |
| ThinkInkDisplays | 10 |
| BreakoutSSD1351 | 10 |
| EInkFeatherWing | 10 |
| BreakoutST7735-160x128 | 10 |
| BreakoutST7789-240x135 | 10 |
| EInkGray29BmpButtonDemo | 10 |
| BreakoutST7789-240x240 | 10 |
| BreakoutST7789-320x240 | 10 |
| BreakoutST7789-280x240 | 10 |
| BreakoutSSD1331 | 10 |
| EInkBreakouts | 10 |
+-----------------------------------+---------------------+
