InitFM6127 does not initialize more than one chain but InitFM6126 does.

[marcmerlin]

I have FM6127 panels. They actually seem to work fine with --led-panel-type=FM6126A When I send --led-panel-type=FM6127, only the first chain is initialized

[marcmerlin]

FM6127 panels are connected as 3 channels

     ,  ch1 - p1 - p4
rpi -   ch2 - p2 - p5
      ` ch3 - p3 - p6

./examples-api-use/demo --led-gpio-mapping=regular --led-rows=64 --led-cols=128 --led-row-addr-type=0 --led-show-refresh --led-slowdown-gpio=2 --led-pwm-bits=7 --led-panel-type=FM6126A --led-parallel=3 --led-pwm-dither-bits=2 --led-pwm-lsb-nanoseconds=100 -D0:

.//examples-api-use/demo --led-gpio-mapping=regular --led-rows=64 --led-cols=128 --led-row-addr-type=0 --led-show-refresh --led-slowdown-gpio=2 --led-pwm-bits=7 --led-panel-type=FM6127 --led-parallel=3 --led-pwm-dither-bits=2 --led-pwm-lsb-nanoseconds=100 -D0:

The 2nd panels in both pictures is chained off the first one and meant to receive a mostly mirrored image (modulo some timing issues since it's receiving planes shifted off the first panel)

[marcmerlin]

@gohlhausen I see you contributed FM6127 support in https://github.com/hzeller/rpi-rgb-led-matrix/issues/964 Can you comment on what you think is going on with the 6127A init sequence and why it would only be going to one channel and not all 3? Reading the code, I don't really see how the init is sent on all channels for FM6126A, but it is: https://github.com/hzeller/rpi-rgb-led-matrix/blob/b8c7cc42e7f5a852ba93c3cc70e4b31e576632c5/lib/framebuffer.cc#L471

[marcmerlin]

@gohlhausen I'm also not too clear on what the FM6127 init does compared to FM6126A. I've been using my FM6127 panels with an FM6126A init so far, and they've seemed fine. I even managed to put an FM6127 panel in the middle of a string of 4 FM6126A panels, and it worked fine too.

[IGR2014]

Guys, maybe the problem is here ?

static void InitFM6126(GPIO *io, const struct HardwareMapping &h, int columns) {
  const gpio_bits_t bits_on
    = h.p0_r1 | h.p0_g1 | h.p0_b1 | h.p0_r2 | h.p0_g2 | h.p0_b2
    | h.p1_r1 | h.p1_g1 | h.p1_b1 | h.p1_r2 | h.p1_g2 | h.p1_b2
    | h.p2_r1 | h.p2_g1 | h.p2_b1 | h.p2_r2 | h.p2_g2 | h.p2_b2
    | h.p3_r1 | h.p3_g1 | h.p3_b1 | h.p3_r2 | h.p3_g2 | h.p3_b2
    | h.p4_r1 | h.p4_g1 | h.p4_b1 | h.p4_r2 | h.p4_g2 | h.p4_b2
    | h.p5_r1 | h.p5_g1 | h.p5_b1 | h.p5_r2 | h.p5_g2 | h.p5_b2
    | h.a;  // Address bit 'A' is always on.

vs:

static void InitFM6127(GPIO *io, const struct HardwareMapping &h, int columns) {
  const gpio_bits_t bits_r_on= h.p0_r1 | h.p0_r2;
  const gpio_bits_t bits_g_on= h.p0_g1 | h.p0_g2;
  const gpio_bits_t bits_b_on= h.p0_b1 | h.p0_b2;
  const gpio_bits_t bits_on= bits_r_on | bits_g_on | bits_b_on;

As you can see, FM6127 only has p0, while FM6126 has p0 .. p5 bits