Found that new structure parmaeter ext_buf_assigned needs to be
initialised to false in lv_chart_add_series() as sometimes is set true
depending on what was previously in the heap where it was allocated.
- change the wording to say "message box" and not "button matrix"
- parameter name should be cb and not xcb due MicroPython
- also corrected comment for lv_async_call in lv_async.h
/**
* Set the index of the x-axis start point in the data array
* @param chart pointer to a chart object
* @param ser pointer to a data series on 'chart'
* @param id the index of the x point in the data array
*/
void lv_chart_set_x_start_point(lv_obj_t * chart, lv_chart_series_t *
ser, uint16_t id);
/**
* Set an external array of data points to use for the chart
* NOTE: It is the users responsibility to make sure the point_cnt
matches the external array size.
* @param chart pointer to a chart object
* @param ser pointer to a data series on 'chart'
* @param array external array of points for chart
*/
void lv_chart_set_ext_array(lv_obj_t * chart, lv_chart_series_t * ser,
lv_coord_t array[], uint16_t point_cnt );
/**
* Set an individual point value in the chart series directly based on
index
* @param chart pointer to a chart object
* @param ser pointer to a data series on 'chart'
* @param value value to assign to array point
* @param id the index of the x point in the array
*/
void lv_chart_set_point_id(lv_obj_t * chart, lv_chart_series_t * ser,
lv_coord_t value, uint16_t id);
/**
* get the current index of the x-axis start point in the data array
* @param chart pointer to a chart object
* @param ser pointer to a data series on 'chart'
* @return the index of the current x start point in the data array
*/
uint16_t lv_chart_get_x_start_point(lv_obj_t * chart, lv_chart_series_t
* ser);
/**
* Get an individual point value in the chart series directly based on
index
* @param chart pointer to a chart object
* @param ser pointer to a data series on 'chart'
* @param id the index of the x point in the array
* @return value of array point at index id
*/
lv_coord_t lv_chart_get_point_id(lv_obj_t * chart, lv_chart_series_t *
ser, uint16_t id);
