schufti wrote:not serial, wifi Tx. Somehow the hf from the esp interfered with the transport from flash to µC. The first working attempt was reducing the flash speed but the final solution was to reduce the wifi power to the limit mentioned in the datasheet. (unfortunately the default in the esp arduino core is too high when going 802.11n)
Sorry misunderstood what you meant in the last post.
Well if I lower the wifi power, hopefully the increase in range I get from moving the antenna off the edge of the PCB will balance.