add rpi_i2c_dump

NAMESPACE

@@ -2,6 +2,7 @@
 
 export(is.rpi)
 export(rpi_get)
+export(rpi_i2c_dump)
 export(rpi_i2c_get)
 export(rpi_i2c_set)
 export(rpi_monitor)

R/rpi_i2c_dump.R

@@ -0,0 +1,32 @@
+#' Read the entire data block from an I2C device
+#'
+#' This is a wrapper to i2cdump.
+#'
+#' @param chip_address an integer between 0x03 and 0x77
+#'
+#' @return the entire memory block from the I2C device
+#' @export
+#'
+#' @examplesIf is.rpi()
+#' rpi_i2c_dump(0x77)
+#'
+rpi_i2c_dump <- function(chip_address) {
+  # Assumes Serial Data Line (SDA, board pin 3)
+  # ...and Serial Clock Line (SCL, board pin 5)
+  # ...therefore i2cbus = 1
+  i2cbus <- 1
+
+  # chip-address must be an integer between 0x03 and 0x77
+  if (missing(chip_address) ||
+      chip_address < 0x03 ||
+      chip_address > 0x77
+  ) {
+    stop("You must specify a chip_address as an integer between 0x08 and 0x77")
+  }
+
+  gpio_sysCall <- paste("i2cdump -y",
+                        i2cbus,
+                        chip_address)
+
+  return(as.integer(system(gpio_sysCall, intern = TRUE)))
+}

tests/testthat/test-rpi_i2c_dump.R

@@ -0,0 +1,3 @@
+test_that("multiplication works", {
+  expect_equal(2 * 2, 4)
+})