Maxim Integrated 7-bit Sink/Source Current DAC. DS4424, DS4422 input/output current Digital-to-Analog Converter Driver/library code.
Dependents: DS4424_Hello_Current_DAC_on_MAX32630FTHR
Diff: DS4424.cpp
- Revision:
- 5:fc75fced724f
- Parent:
- 4:3824afaf0d61
--- a/DS4424.cpp Sun Oct 07 22:13:14 2018 +0000 +++ b/DS4424.cpp Wed Jan 23 00:43:09 2019 +0000 @@ -1,5 +1,5 @@ /******************************************************************************* - * Copyright (C) 2018 Maxim Integrated Products, Inc., All Rights Reserved. + * Copyright (C) 2018-2019 Maxim Integrated Products, Inc., All Rights Reserved. * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), @@ -32,6 +32,10 @@ */ #include "DS4424.h" +/* #include "USBSerial.h" */ +#define DS4424_U8_MAX ((uint8_t)~0U) +#define DS4424_S8_MAX ((int8_t)(DS4424_U8_MAX>>1)) +#define DS4424_S8_MIN ((int8_t)(-DS4424_S8_MAX - 1)) /* * DS4424 DAC control register 8 bits @@ -84,7 +88,7 @@ union ds4424_raw_data raw; if (chan_addr >= REG_OUT0 && chan_addr <= m_max_ch_reg_addr) - ret = read_register(chan_addr, value); + ret = read_register(value, chan_addr); if (ret != 0) return DS4424_ERROR; @@ -98,6 +102,23 @@ } + +/******************************************************************************/ +int DS4424::read_hw_raw(uint8_t &result, ChannelRegAddr_e chan_addr) +{ + uint8_t value; + int ret = DS4424_ERROR; + + if (chan_addr >= REG_OUT0 && chan_addr <= m_max_ch_reg_addr) + ret = read_register(value, chan_addr); + if (ret != 0) + return DS4424_ERROR; + + result = value; + return DS4424_NO_ERROR; +} + + /******************************************************************************/ int DS4424::write_raw(int32_t value, ChannelRegAddr_e chan_addr) { @@ -126,9 +147,90 @@ } } + + +/******************************************************************************/ +int DS4424::write_hw_raw(uint8_t value, ChannelRegAddr_e chan_addr) +{ + int ret = DS4424_ERROR; + if (chan_addr >= REG_OUT0 && chan_addr <= m_max_ch_reg_addr) { + ret = write_register(chan_addr, value); + if (ret != 0) + return DS4424_ERROR; + return DS4424_NO_ERROR; + } else { + return DS4424_ERROR; + } +} + + /******************************************************************************/ -int DS4424::read_register(ChannelRegAddr_e reg, uint8_t &value) +int DS4424::convert_picoAmps_to_hw_raw(uint8_t *val_out, + int32_t picoAmps, uint32_t rfs_resistor) +{ + uint32_t val, tmp_scale, round_up; + union ds4424_raw_data raw; + + /* val can be 0 to 200,000,000 (200 picoAmps) */ + val = picoAmps; + raw.source_bit = DS4424_SOURCE_I; + if (picoAmps < 0) { + raw.source_bit = DS4424_SINK_I; + val = -picoAmps; + } + if (val > DS4424_MAX_PICOAMPS || + rfs_resistor < DS4424_MIN_RFS || + rfs_resistor > DS4424_MAX_RFS) + return DS4424_ERROR; + rfs_resistor /= 100; + val = val / 1000; + + tmp_scale = DS4424_IFS_SCALE / 10; + round_up = tmp_scale / 2; + val = ((val * rfs_resistor) + round_up) / + tmp_scale; + + val = val / 100; + if (val > DS4424_S8_MAX) { + printf("%s : Requested current %d\r\n", + __func__, val); + printf("exceeds maximum. DAC set to maximum %d\n\r\n", + DS4424_S8_MAX); + val = DS4424_S8_MAX; + } + raw.dx = val; + *val_out = raw.bits; + return DS4424_NO_ERROR; + +} + + +/******************************************************************************/ +int DS4424::convert_raw_to_picoAmps(int32_t *val_out, + int8_t raw_in, uint32_t rfs_resistor) +{ + uint32_t round_up; + union ds4424_raw_data raw; + if (rfs_resistor < DS4424_MIN_RFS || rfs_resistor > DS4424_MAX_RFS) { + return DS4424_ERROR; + } + rfs_resistor /= 100; + + raw.bits = raw_in; + *val_out = DS4424_IFS_SCALE * raw.dx * 10; + round_up = rfs_resistor / 2; + *val_out = (*val_out + round_up) / rfs_resistor; + + if (raw.source_bit == DS4424_SINK_I) + *val_out = -*val_out; /* this routine use negatives if sinking */ + *val_out = *val_out * 1000; /* picoAmps */ + return DS4424_NO_ERROR; +} + + +/******************************************************************************/ +int DS4424::read_register(uint8_t &value, ChannelRegAddr_e reg) { int32_t ret;