From 641ed2a092df959f478390c52f90837b30a5332c Mon Sep 17 00:00:00 2001
From: jaseg <git@jaseg.net>
Date: Fri, 27 Apr 2018 13:58:42 +0200
Subject: Make channel count configurable

---
 firmware/global.h | 2 +-
 firmware/main.c   | 8 +++++---
 firmware/serial.h | 2 +-
 3 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/firmware/global.h b/firmware/global.h
index 3e585f6..0098d38 100644
--- a/firmware/global.h
+++ b/firmware/global.h
@@ -21,7 +21,7 @@
  * in main.c.  */
 #define NBITS 14
 
-#define NCHANNELS 32
+#define NCHANNELS 8
 #define CHANNEL_SPEC 'H'
 #define COLOR_SPEC COLOR_SPEC_RGBW
 #define DEVICE_TYPE OLSNDOT_V1
diff --git a/firmware/main.c b/firmware/main.c
index ec56767..c6a4ac9 100644
--- a/firmware/main.c
+++ b/firmware/main.c
@@ -253,7 +253,7 @@ void do_transpose(void) {
     for (uint32_t i=0; i<NBITS; i++) {
         uint32_t mask = 1<<i<<(MAX_BITS-NBITS); /* Bit mask for this bit value. */
         uint32_t bv = 0; /* accumulator thing */
-        for (uint32_t j=0; j<32; j++)
+        for (uint32_t j=0; j<NCHANNELS; j++)
             if (rx_buf.set_fb_rq.framebuf[j] & mask)
                 bv |= 1<<j;
         brightness_by_bit[i] = bv;
@@ -287,10 +287,12 @@ void TIM1_BRK_UP_TRG_COM_IRQHandler(void) {
          * capture/compare channel 3 complementary outputs. The dead-time generator is used to sequence the clear and
          * strobe edges one after another. Since there may be small variations in IRQ service latency it is critical to
          * allow for some leeway between the end of this data transmission and strobe and clear. */
-        SPI1->DR = (val&0xffff);
-        while (SPI1->SR & SPI_SR_BSY);
+#if NCHANNELS > 16
         SPI1->DR = (val>>16);
         while (SPI1->SR & SPI_SR_BSY);
+#endif
+        SPI1->DR = (val&0xffff);
+        while (SPI1->SR & SPI_SR_BSY);
 
         /* Increment the bit index for the next cycle */
         idx++;
diff --git a/firmware/serial.h b/firmware/serial.h
index 94cfd57..96d0e70 100644
--- a/firmware/serial.h
+++ b/firmware/serial.h
@@ -64,7 +64,7 @@ union rx_buf_union {
      *                                 |<----------------NBITS---------------->|  |<>|--ignored
      *                                 | (MSB)      brightness data      (LSB) |  |<>|--ignored
      */
-    struct __attribute__((packed)) { uint16_t framebuf[32]; uint8_t end[0]; } set_fb_rq;
+    struct __attribute__((packed)) { uint16_t framebuf[NCHANNELS]; uint8_t end[0]; } set_fb_rq;
     uint8_t byte_data[0];
     uint32_t mac_data;
 };
-- 
cgit