are there any stable libraries for IIR (recursive) filters for the STM32F4x, aside of the CMSIS DSP software library? The CMSIS has only lattice (arm_iir_lattice***) or biquad (arm_biquad_cascade***) implementations. I'm simply looking for a straightforward regular implementation with recursive b[n] and a[n] coefficients. Only up to n=5 or 6, so the biquad functions are an overkill; plus, I would like to avoid having to calculate the coefficients (I've got tons of filters in standard recursive form).
