https://martantoine.github.io/tags/stm32f4/Recent content in STM32F4 on Antoine Martin's BlogHugo -- gohugo.ioen-usSat, 11 Sep 2021 00:00:00 +0000https://martantoine.github.io/posts/sas/Sat, 11 Sep 2021 00:00:00 +0000https://martantoine.github.io/posts/sas/<h2 id="introduction">Introduction</h2> <h3 id="requirements">Requirements:</h3> <ul> <li>Support up to 16 sensors simultaneous</li> <li>Support different kind of sensors, must be easily upgradable to support new ones</li> <li>Independent conditioning of the signal for each sensor (1 board per sensor)</li> <li>Transmit the data to the computer which will log it</li> <li>Settings must be set from the computer</li> <li>Sampling rate of 1kHz</li> <li>Resolution of 16bits</li> <li>Required supported sensors: <ul> <li>force sensor using Wheastone bridge</li> <li>Thermocouple</li> <li>Pressure sensor</li> </ul> </li> </ul> <h2 id="project-architecture">Project Architecture</h2> <div style="text-align: center; margin: 1.5rem 0;"> <img src="https://martantoine.github.io/posts/sas/architecture.PNG" alt="" loading="lazy" style="max-width: 100%; height: auto;"> </div> <h2 id="components">Components</h2> <p>The list of components used has changed quite a lot thorough the design, I will for the sake of clarity only talk about the final design choice.</p> <h3 id="analog-to-digital-converter">Analog to Digital Converter</h3> <p>Accordingly to the requirements, the ADC must have 16 physical pins to which the sensors would be always connected. Moreover it has to sample each 16 sensors at a resolution of 16 bits at 1kHz.</p> <h3 id="mcu">MCU</h3> <p>The MCU must validates the following requirements:</p> <ul> <li>2 SPI interface of at least 256 kbits/s (one for the ADC, the other for the USB port)</li> <li>be of the STM32 family (since it&rsquo;s the one mostly used at the ERT)</li> <li>handle a SPI data traffic of 256 kbits/s from the ADC</li> </ul> <p>In order to reduce the workload on the PCB design, the MCU must be already assembled on a board featuring :</p> <ul> <li>USB interface for transmitting data/debugging/programming of the MCU</li> <li>Header pins such that it can plugged as a shield on the main PCB board</li> </ul> <p>The chosen MCU is the Nucleo STM32 F446RE.</p> <h3 id="power-supply">Power Supply</h3> <p>Many voltages are needed : 5V, 3.3V, 9V, 12V.</p> <h2 id="hostboard-a">Hostboard A</h2> <p> <div style="text-align: center; margin: 1.5rem 0;"> <img src="https://martantoine.github.io/posts/sas/Hostboard_A_schema.PNG" alt="" loading="lazy" style="max-width: 100%; height: auto;"> </div> <div style="text-align: center; margin: 1.5rem 0;"> <img src="https://martantoine.github.io/posts/sas/Hostboard_A_pcb3D_1.PNG" alt="" loading="lazy" style="max-width: 100%; height: auto;"> </div> <div style="text-align: center; margin: 1.5rem 0;"> <img src="https://martantoine.github.io/posts/sas/Hostboard_A_pcb3D_2.PNG" alt="" loading="lazy" style="max-width: 100%; height: auto;"> </div> PCBs assembly <div style="text-align: center; margin: 1.5rem 0;"> <img src="https://martantoine.github.io/posts/sas/hostboard_raw.JPG" alt="" loading="lazy" style="max-width: 100%; height: auto;"> </div> Assembled PCBs with test pcb <div style="text-align: center; margin: 1.5rem 0;"> <img src="https://martantoine.github.io/posts/sas/hostboard_assembled.JPG" alt="" loading="lazy" style="max-width: 100%; height: auto;"> </div> </p> <h2 id="daugtherboard">Daugtherboard</h2> <p> <div style="text-align: center; margin: 1.5rem 0;"> <img src="https://martantoine.github.io/posts/sas/Daughterboard_schema.PNG" alt="" loading="lazy" style="max-width: 100%; height: auto;"> </div> <div style="text-align: center; margin: 1.5rem 0;"> <img src="https://martantoine.github.io/posts/sas/Daughterboard_pcb3D_1.PNG" alt="" loading="lazy" style="max-width: 100%; height: auto;"> </div> <div style="text-align: center; margin: 1.5rem 0;"> <img src="https://martantoine.github.io/posts/sas/Daughterboard_pcb3D_2.PNG" alt="" loading="lazy" style="max-width: 100%; height: auto;"> </div> </p> <h2 id="pcbs-assembly">PCBs assembly</h2> <div style="text-align: center; margin: 1.5rem 0;"> <img src="https://martantoine.github.io/posts/sas/PCBs_assembly.PNG" alt="" loading="lazy" style="max-width: 100%; height: auto;"> </div>