I would like to update the ARR of TIM2 after each overflow is reached. I tried this with HAL_TIM_Start_DMA, but it only seems to start the timer; the timer period elapsed callback is never reached. I have set the interrupts for the timer and DMA channel. The DMA channel is set up memory to peripheral, incrementing memory address, with word transfer size. What could be the problem that is preventing the callback from being reached? Does anyone know of code that demonstrates using the HAL libraries for this?