/*! LTC2418: 16-Channel 24-Bit No Latency Delta-Sigma ADC @verbatim The LTC2414/LTC2418 are 8-/16-channel (4-/8-differential) micropower 24-bit delta-sigma analog-to-digital converters. They operate from 2.7V to 5.5V and include an integrated oscillator, 2ppm INL and 0.2ppm RMS noise. They use delta-sigma technology and provide single cycle settling time for multiplexed applications. Through a single pin, the LTC2414/LTC2418 can be configured for better than 110dB differential mode rejection at 50Hz or 60Hz +/-2%, or they can be driven by an external oscillator for a user-defined rejection frequency. The internal oscillator requires no external frequency setting components. SPI DATA FORMAT (MSB First): Byte #1 Byte #2 Byte #3 Byte #4 Data Out : !EOC DMY SIG D22 D21 D20 D19 D18 D17 D16 D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 SGL OS S2 S1 S0 PAR Data In : 1 0 EN SGL OS S2 S1 S0 X X X X X X X X X X X X X X X X X X X X X X X X !EOC : End of Conversion Bit (Active Low) DMY : Dummy Bit (Always 0) SIG : Sign Bit (1-data positive, 0-data negative) Dx : Data Bits EN : Enable Bit (0-keep previous mode, 1-change mode) SGL : Enable Single-Ended Bit (0-differential, 1-single-ended) OS : ODD/Sign Bit Sx : Address Select Bit PAR : Parity Bit Command Byte 1 0 EN SGL OS S2 S1 S0 Comments 1 0 0 X X X X X Keep Previous Mode 1 0 1 0 X X X X Differential Mode 1 0 1 1 X X X X Single-Ended Mode Example Code: Read Channel 0 in Single-Ended mode uint16_t miso_timeout = 1000; adc_command = LTC2418_CH0; // Build ADC command for channel 0 if(LTC2418_EOC_timeout(LTC2418_CS, miso_timeout)) // Check for EOC return(1); LTC2418_read(LTC2418_CS, adc_command, &adc_code); // Throws out last reading if(LTC2418_EOC_timeout(LTC2418_CS, miso_timeout)) // Check for EOC return(1); LTC2418_read(LTC2418_CS, adc_command, &adc_code); // Obtains the current reading and stores to adc_code variable // Convert adc_code to voltage adc_voltage = LTC2418_code_to_voltage(adc_code, LTC2418_lsb , LTC2418_offset_code); @endverbatim http://www.linear.com/product/LTC2418 http://www.linear.com/product/LTC2418#demoboards Copyright 2018(c) Analog Devices, Inc. All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: - Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. - Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. - Neither the name of Analog Devices, Inc. nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. - The use of this software may or may not infringe the patent rights of one or more patent holders. This license does not release you from the requirement that you obtain separate licenses from these patent holders to use this software. - Use of the software either in source or binary form, must be run on or directly connected to an Analog Devices Inc. component. THIS SOFTWARE IS PROVIDED BY ANALOG DEVICES "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL ANALOG DEVICES BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, INTELLECTUAL PROPERTY RIGHTS, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /*! @file @ingroup LTC2418 Header for LTC2418: 16-Channel 24-Bit No Latency Delta-Sigma ADC */ #ifndef LTC2418_H #define LTC2418_H #include //! Define the SPI CS pin #ifndef LTC2418_CS #define LTC2418_CS QUIKEVAL_CS #endif //! @name LTC2418 Single-Ended configuration bytes //! @{ //! Address bytes with enable sequence prepended #define LTC2418_CH0 0xB0 #define LTC2418_CH1 0xB8 #define LTC2418_CH2 0xB1 #define LTC2418_CH3 0xB9 #define LTC2418_CH4 0xB2 #define LTC2418_CH5 0xBA #define LTC2418_CH6 0xB3 #define LTC2418_CH7 0xBB #define LTC2418_CH8 0xB4 #define LTC2418_CH9 0xBC #define LTC2418_CH10 0xB5 #define LTC2418_CH11 0xBD #define LTC2418_CH12 0xB6 #define LTC2418_CH13 0xBE #define LTC2418_CH14 0xB7 #define LTC2418_CH15 0xBF //! @} //! @name LTC2418 Differential configuration bytes //! @{ //! Address bytes with enable sequence prepended #define LTC2418_P0_N1 0xA0 #define LTC2418_P1_N0 0xA8 #define LTC2418_P2_N3 0xA1 #define LTC2418_P3_N2 0xA9 #define LTC2418_P4_N5 0xA2 #define LTC2418_P5_N4 0xAA #define LTC2418_P6_N7 0xA3 #define LTC2418_P7_N6 0xAB #define LTC2418_P8_N9 0xA4 #define LTC2418_P9_N8 0xAC #define LTC2418_P10_N11 0xA5 #define LTC2418_P11_N10 0xAD #define LTC2418_P12_N13 0xA6 #define LTC2418_P13_N12 0xAE #define LTC2418_P14_N15 0xA7 #define LTC2418_P15_N14 0xAF //! @} //! Checks for EOC with a specified timeout //! @return 0=successful, 1=unsuccessful (exceeded timeout) int8_t LTC2418_EOC_timeout(uint8_t cs, //!< Chip Select pin uint16_t miso_timeout //!< Timeout (ms) ); //! Reads the LTC2418 result and programs the configuration for the next conversion. //! @return void void LTC2418_read(uint8_t cs, //!< Chip Select pin uint8_t adc_command, //!< Command byte uint32_t *adc_code //!< Returns raw 32-bit code read from ADC ); //! Calculates the LTC2418 input bipolar voltage //! @return Calculated voltage float LTC2418_code_to_voltage(int32_t adc_code, //!< Raw ADC code float LTC2418_lsb, //!< LSB value (volts) int32_t LTC2418_offset_code //!< Offset (Code) ); //! Calibrate the lsb //! @return Void void LTC2418_cal_voltage(int32_t zero_code, //!< Offset (Code) int32_t fs_code, //!< Code measured with full-scale input applied float zero_voltage, //!< Measured zero voltage float fs_voltage, //!< Measured full-scale voltage float *LTC2418_lsb, //!< Returns LSB value (volts) int32_t *LTC2418_offset_code //!< Returns Offset (Code) ); #endif // LTC2418_H