From 61e4deff3867b515d7ce96278410ea376b55c86e Mon Sep 17 00:00:00 2001
From: Jan Breuer <jan.breuer@jaybee.cz>
Date: 周二, 04 12月 2012 18:09:37 +0800
Subject: [PATCH] Update README - new way of initialization
---
README.md | 24 +++++++++++++++---------
1 files changed, 15 insertions(+), 9 deletions(-)
diff --git a/README.md b/README.md
index 7565661..2a495c5 100644
--- a/README.md
+++ b/README.md
@@ -58,6 +58,7 @@
scpi_command_t scpi_commands[] = {
{ .pattern = "*IDN?", .callback = SCPI_CoreIdnQ,},
{ .pattern = "*RST", .callback = SCPI_CoreRst,},
+ { .pattern = "MEASure:VOLTage:DC?", .callback = DMM_MeasureVoltageDcQ,},
SCPI_CMD_LIST_END
};
@@ -68,28 +69,33 @@
.error = NULL,
.reset = NULL,
.test = NULL,
+ .srq = NULL,
};
Important thing is command buffer. Maximum size is up to you and it should be larger than any possible largest command.
- #define SCPI_BUFFER_LENGTH 256
- char myBuffer[SCPI_BUFFER_LENGTH];
+ #define SCPI_INPUT_BUFFER_LENGTH 256
+ static char scpi_input_buffer[SCPI_INPUT_BUFFER_LENGTH];
- scpi_buffer_t scpi_buffer = {
- .length = SCPI_BUFFER_LENGTH,
- .data = myBuffer,
- };
The last structure is scpi context used in parser library.
- scpi_t scpi_context;
+ scpi_t scpi_context = {
+ .cmdlist = scpi_commands,
+ .buffer = {
+ .length = SCPI_INPUT_BUFFER_LENGTH,
+ .data = scpi_input_buffer,
+ },
+ .interface = &scpi_interface,
+ .registers = scpi_regs,
+ };
All these structures should be global variables of the c file or allocated by function like malloc. It is common mistake to create these structures inside a function as local variables of this function. This will not work. If you don't know why, you should read something about [function stack.](http://stackoverflow.com/questions/4824342/returning-a-local-variable-from-function-in-c).
-Now we are ready to connect everything together
+Now we are ready to initialize SCPI context. It is possible to use more SCPI contexts and share some configurations (command list, registers, units list, error callback...)
- SCPI_Init(&scpi_context, scpi_commands, &scpi_buffer, &scpi_interface);
+ SCPI_Init(&scpi_context);
Test implementation of function myWrite, which outputs everything to stdout, can be
--
Gitblit v1.9.1