![]() No memes (pictures with superimposed text), shit posts.No spam no commercial posts, links to commercial pages (including crowd funding sites), no employment ads (job offers and requests go to the weekly thread), no self-promotion (*).If asking a question, ask the actual question, fully yet concisely, right in the title.Be civil: do not insult no all-caps, no excessive "!" and "?", please.Questions on employment (career, internship), education (major, certificates), how to start in embedded.Job announcements (outside the monthly job thread).High level software (e.g., C#, Javascript): r/softwaredevelopment, r/software.Single Board computers: r/Raspberry_pi, r/Arduino, r/linux_devices, r/linuxboards.Hardware design that does not include a micro for electronic circuits: /r/AskElectronics.Homework help but make it clear it's homework.The signal from TCD1304 comes, but strange or all bright, or everything is dark.This sub is dedicated to discussion and questions about embedded systems: "a controller programmed and controlled by a real-time operating system (RTOS) with a dedicated function within a larger mechanical or electrical system, often with real-time computing constraints." FAQ I checked the signal generation and the operation of the ADC – all is correct. tDMA (dataOS, maxSamples, (DMA_MINC_MODE | DMA_CIRC_MODE), NULL) tContinuous () // set the ADC in continuous mode. tPins (pinsOS, maxSamples) // set how many and which pins to convert. tScanMode () // set the ADC in Scan mode. tSampleRate (ADC_SMPR_1_5) // set the Sample Rate If (count = 6) gpio_write_bit (ICG_p, ICG_d, HIGH) If (count% (4) = 2) gpio_write_bit (SH_p, SH_d, LOW) If (count% (4) = 0) gpio_write_bit (SH_p, SH_d, HIGH) If (count = 0) gpio_write_bit (ICG_p, ICG_d, LOW) Set the timer:įtPrescaleFactor (90) // 0.8 MHzįmtimer.attachCompare2Interrupt (read_ccd) Hello! I’m trying to implement the project on STM32F103. I included a few bits of explanation if you want to play yourself or simply learn more.ĭon’t forget to read my posts Programming an ARM-processor (I) and (II)to get a working compiler-environment ready to type make. In the meantime you can enjoy yourself with the source code for driving the TCD1304 with the STM32F401RE Nucleo board. Next up is setting up two other pieces of the M4’s peripherals: I need the DMA controller to pick up all those delicious pixelreadings from the ADC. I was hoping to see exactly during which of the four clock cycles the CCD would feed me the output, but I don’t really feel smarter Īs with women there are still many things I don’t quite understand about CCD’s. Here’s a plot of the CCD master clock (running at 1.4 MHz) with the output signal at every 4th clock cycle: The datasheet finally makes more sense to me (though I still find it confusing that ICG period is called the readout time, when clearly all reading is done 10.6 ms after each ICG pulse). The SH is not shown but here it runs with a period of only 400 µs.Īpparently the SH and ICG need only fulfill the requirements when both trigger, and SH does indeed control the integration time. It’s my first 1D-selfie! The red line is the ICG-pulse running with a period of 40 ms and the blue is the output from the CCD. On two other GPIOs not shown here are the master clock, running at 1.4 MHz, and the ADC clock at 350 kHz. The blue line is the SH pulse and the red is the ICG pulse. ![]() However, having the Cortex-M4 timers, it proved quite manageable, and after waking up one night remembering an ARM timing register called something-Polarity and only a few trial runs, I finally had this: However, these application notes from Toshiba explain the different pulses a little better, and the datasheets for similar chips – namely the TCD1254 and TCD1103 – are also instructive.Įven though I felt smarter after reading I still had a nagging suspicion it would be a small nightmare to fulfill the timing criteria of the chip. This, together with the timing diagram in the previous post, is about as much information the datasheet provides. Here are the timing requirements for the TCD1304: And as with women timing is everything with CCD’s. For an up-to-date version and a more well structured presentation go to tcd1304.wordpressĬCD’s are just like women, demanding but wonderful creatures. This post from 2015 introduced the very first firmware for driving the tcd1304dg.
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