serial-dmm: Expand a code comment.

[libsigrok.git] / src / hardware / serial-dmm / api.c

diff --git a/src/hardware/serial-dmm/api.c b/src/hardware/serial-dmm/api.c
index 8047b09a3f79f3d01721a32fc4add020dbba50ec..5a2f13f104d9cd69ed6d557441158bc39879eba9 100644 (file)
--- a/src/hardware/serial-dmm/api.c
+++ b/src/hardware/serial-dmm/api.c
@@ -263,16 +263,23 @@ SR_REGISTER_DEV_DRIVER_LIST(serial_dmm_drivers,
                sr_es519xx_2400_11b_packet_valid, sr_es519xx_2400_11b_parse,
                NULL
        ),
+       /*
+        * Note: ES51922 and ES51986 baudrate is actually 19230. This is
+        * "out" by .15%, and so is well within the typical 1% margin
+        * that is considered acceptable in UART communication, and thus
+        * should not cause an issue.
+        *
+        * However, using 19230 as baudrate here will not work, as most DMM
+        * cables do not support that baudrate!
+        */
        DMM(
                "tenma-72-7750-ser", es519xx,
-               /* Note: ES51986 baudrate is actually 19230! */
                "Tenma", "72-7750 (UT-D02 cable)", "19200/7o1/rts=0/dtr=1",
                19200, ES519XX_11B_PACKET_SIZE, 0, 0, NULL,
                sr_es519xx_19200_11b_packet_valid, sr_es519xx_19200_11b_parse,
                NULL
        ),
        DMM(
-               /* Note: ES51986 baudrate is actually 19230! */
                "uni-t-ut60g-ser", es519xx,
                "UNI-T", "UT60G (UT-D02 cable)", "19200/7o1/rts=0/dtr=1",
                19200, ES519XX_11B_PACKET_SIZE, 0, 0, NULL,
@@ -281,7 +288,6 @@ SR_REGISTER_DEV_DRIVER_LIST(serial_dmm_drivers,
        ),
        DMM(
                "uni-t-ut61e-ser", es519xx,
-               /* Note: ES51922 baudrate is actually 19230! */
                "UNI-T", "UT61E (UT-D02 cable)", "19200/7o1/rts=0/dtr=1",
                19200, ES519XX_14B_PACKET_SIZE, 0, 0, NULL,
                sr_es519xx_19200_14b_packet_valid, sr_es519xx_19200_14b_parse,
@@ -583,11 +589,15 @@ SR_REGISTER_DEV_DRIVER_LIST(serial_dmm_drivers,
                sr_ut71x_packet_valid, sr_ut71x_parse, NULL
        ),
        /* }}} */
-       /* meters based on other chips (to get sorted) */
+       /* vc870 based meters {{{ */
        DMM(
                "voltcraft-vc870-ser", vc870,
                "Voltcraft", "VC-870 (UT-D02 cable)", "9600/8n1/rts=0/dtr=1",
                9600, VC870_PACKET_SIZE, 0, 0, NULL,
                sr_vc870_packet_valid, sr_vc870_parse, NULL
        ),
+       /* }}} */
+       /*
+        * The list is sorted. Add new items in the respective chip's group.
+        */
 );