ESP32 no display with 32x64 RGB

gsallen103 · May 12, 2020, 5:09pm

I’m trying to get a 64x32 RGB display working with an ESP32. I’m just trying the demo examples and I just have a blank display.

I can get the display to work with a ESP32-RGB64x32MatrixPanel-I2S-DMA.

I’ve tried using the ESP32_FORUM_PINOUT and got nothing. I’ve tried changing all the pin maps to the I2S-DMA pin maps and still get nothing.

Is there a way I can slow the clock down or something to validate that the connectivity works?
I’m planning to get a custom PCB, so I need to validate functionality before getting it fabricated.

Louis · May 12, 2020, 8:54pm

github.com

pixelmatix/SmartMatrix/blob/teensylc/src/MatrixHardware_ESP32_V0.h#L29


* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/


// Note: only one MatrixHardware_*.h file should be included per project


#ifndef MATRIX_HARDWARE_H
#define MATRIX_HARDWARE_H
// formula used is 80000000L/(cfg->clkspeed_hz + 1), must result in >=2.  Acceptable values 26.67MHz, 20MHz, 16MHz, 13.34MHz...
#define ESP32_I2S_CLOCK_SPEED (20000000UL)


#define ESP32_FORUM_PINOUT              0
#define ESP32_FORUM_PINOUT_WITH_LATCH   1
#define SMARTLED_SHIELD_V0_PINOUT       2
#define ESP32_JC_RIBBON_PINOUT          3
#define HUB75_ADAPTER_PINOUT            4
#define HUB75_ADAPTER_LATCH_BREADBOARD_PINOUT            5
#define HUB75_ADAPTER_V0_THT_PINOUT     6
#define HUB75_ADAPTER_V0_SMT_PINOUT     7
#define ESP32_JC_RIBBON_PINOUT_WEMOS    8

Not sure what could be wrong. Can you paste the configuration section of the Bitmaps sketch, modified for your panel?

gsallen103 · May 13, 2020, 12:24am

Thank you for the suggestion. I tried the Bitmaps sketch and noticed that it was set to SMARTMATRIX_HUB75_32ROW_MOD16SCAN. When I made that change things started working normally.
I’ve got a small number of ghosted pixels and other artifacts, but that’s probably a consequence of no level shifters and moderately long cables (they get better or worse with moving the cable).