Diff: main.cpp

Revision:

27:a45d6e38f2de

Parent:

26:33c0d3fd2a95

Child:

28:315604f4b374

--- a/main.cpp	Wed Jun 23 21:36:13 2021 +0000
+++ b/main.cpp	Wed Jun 23 22:05:36 2021 +0000
@@ -150,6 +150,12 @@
 /*****************************************************************************/
 // read_sh_fifo
 /*****************************************************************************/
+/*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*/
+//#define OPTIMIZE_FIFO_READ 1  // Assume that the FIFO is filled at the specified rate, so just periodically check then number of samples in the FIFO to save power
+#ifdef OPTIMIZE_FIFO_READ     // tested on MAXM86146EVSYS
+    int32_t check_fifo_countdown;
+    #define MAX_FIFO_CNT 20
+#endif
 void read_sh_fifo(void) {
     char cmd[8], i, j, samples;
     char rsp[3000];
@@ -167,26 +173,39 @@
     int32_t sptr = 0;
     mfio = 0; wait_us(300);
     Time_to_Read_PPG = 0;
+#if defined(OPTIMIZE_FIFO_READ)
+    check_fifo_countdown--;
+    samples = 1;
+    scnt = 1;
+    if (check_fifo_countdown == 0) {
+#endif
+
 #if defined(MAXREFDES103_CFG) || defined(MAXM86161_CFG)
 // 2.1
-    cmd[0] = 0x00; cmd[1] = 0x00;
-    sh_i2c.write(SH_ADDR, cmd, 2);
-    wait_us(100);
-    sh_i2c.read(SH_ADDR, rsp, 2);
-//    pc.printf("2.1 Status: %x %x\n\r", rsp[0], rsp[1]);
+        cmd[0] = 0x00; cmd[1] = 0x00;
+        sh_i2c.write(SH_ADDR, cmd, 2);
+        wait_us(100);
+        sh_i2c.read(SH_ADDR, rsp, 2);
+//        pc.printf("2.1 Status: %x %x\n\r", rsp[0], rsp[1]);
 #else
     // testd 33.13.12 doesn't need 2.1
 #endif
 // 2.2
-    cmd[0] = 0x12; cmd[1] = 0x00;
-    sh_i2c.write(SH_ADDR, cmd, 2);
-    wait_us(100);
-    sh_i2c.read(SH_ADDR, rsp, 2);
-//    pc.printf("2.2 Status: %x %x\n\r", rsp[0], rsp[1]);
-    samples = rsp[1];
-//    pc.printf("num samples %d, (num*ttl)+1 %d\n\r",  rsp[1], TTL_SZ*samples+1);
-//    pc.printf("num smpls %d \n\r",  samples);
-    scnt = rsp[1];
+        cmd[0] = 0x12; cmd[1] = 0x00;
+        sh_i2c.write(SH_ADDR, cmd, 2);
+        wait_us(100);
+        sh_i2c.read(SH_ADDR, rsp, 2);
+//      pc.printf("2.2 Status: %x %x\n\r", rsp[0], rsp[1]);
+        samples = rsp[1];
+//      pc.printf("num samples %d, (num*ttl)+1 %d\n\r",  rsp[1], TTL_SZ*samples+1);
+//      pc.printf("num smpls %d \n\r",  samples);
+        scnt = rsp[1];
+#if defined(OPTIMIZE_FIFO_READ)
+    }
+    if (check_fifo_countdown <= 0)
+        check_fifo_countdown = MAX_FIFO_CNT;
+#endif
+
 // 2.3
     cmd[0] = 0x12; cmd[1] = 0x01;
     sh_i2c.write(SH_ADDR, cmd, 2);
@@ -320,7 +339,7 @@
             ibi_offset = rsp[ptr+20];
 
             sptr += (TTL_SZ);
-#if 1
+#if 0
             pc.printf("%d,%d,%d,%d,", opmode, hr, hr_conf, ibi);
             pc.printf("%d,%d,%d,%d,", ibi_conf, act, r, spo2_conf);
             pc.printf("%d,%d,%d,%d,", spo2, spo2_compl, spo2_lo, spo2_mo);
@@ -374,6 +393,11 @@
 void init_sh_algo(void) {
     char cmd[8];
     char rsp[256];
+
+#ifdef OPTIMIZE_FIFO_READ
+    check_fifo_countdown = MAX_FIFO_CNT;
+#endif
+
     // switch to application mode
     rst = 0;
     mfio = 1;