hantek-dso: fix triggerpoint conversion

[libsigrok.git] / hardware / hantek-dso / dso.c

diff --git a/hardware/hantek-dso/dso.c b/hardware/hantek-dso/dso.c
index 1ad30f097c36eb83bd65b5822c0451584104e49e..75832c8aa4e98806a9dd35dea971259c7714a4dd 100644 (file)
--- a/hardware/hantek-dso/dso.c
+++ b/hardware/hantek-dso/dso.c
@@ -643,7 +643,8 @@ SR_PRIV int dso_init(struct context *ctx)
 SR_PRIV int dso_get_capturestate(struct context *ctx, uint8_t *capturestate,
                uint32_t *trigger_offset)
 {
-       int ret, tmp;
+       int ret, tmp, i;
+       unsigned int bitvalue, toff;
        uint8_t cmdstring[2], inbuf[512];
 
        sr_dbg("hantek-dso: sending CMD_GET_CAPTURESTATE");
@@ -663,7 +664,20 @@ SR_PRIV int dso_get_capturestate(struct context *ctx, uint8_t *capturestate,
                return SR_ERR;
        }
        *capturestate = inbuf[0];
-       *trigger_offset = (inbuf[1] << 16) | (inbuf[3] << 8) | inbuf[2];
+       toff = (inbuf[1] << 16) | (inbuf[3] << 8) | inbuf[2];
+
+       /* This conversion comes from the openhantek project.
+        * Each set bit in the 24-bit value inverts all bits with a lower
+        * value. No idea why the device reports the trigger point this way.
+        */
+       bitvalue = 1;
+       for (i = 0; i < 24; i++) {
+               // Each set bit inverts all bits with a lower value
+               if(toff & bitvalue)
+                       toff ^= bitvalue - 1;
+               bitvalue <<= 1;
+       }
+       *trigger_offset = toff;
 
        return SR_OK;
 }