Continuing my last time research on new NFC ICs I've obtained a OM5578 board [Arduino pinout] and PN7150 USB Dongle from Mikroelektronika. The Dongle itself was communicating with an USB through LPC11U24 uC. As a ready product it worked well. Then came a time to dismount a uC and to try merging a PN7150 with a HID USB to SMBus/I2C bridge: CP2112-EK from Silicon Labs. The task was to interface a PN7150 with an i2c master circuit that way it would not require additional uC programming [only an app running on linux].
A problem I've encountered is an inability to detect a PN7150 via I2C. Neither dismounted Dongle nor OM5578 can be seen when i2cdetect runs. I2C bridge actually works correctly - e.g. AT24C01A EEPROM is being detected correctly.
Basing on available circuits:
The OM5578 is wired to CP2112-EK as follows:
VBAT+PVDD -> 3.3V
VANT -> 5V
VEN -> 3.3V
SCL -> SCL
SDA -> SDA
GND -> GND
IRQ -> floating
The actual measurement of 3.3 line shows up to 3.6 but it remains within the working range.
1.) Am I missing some connection here?
2.) Is there a chance I've fried both PNs?
3.) Is there perhaps a peculiar timing required to turn the VEN on or an ON/OFF sequence?
4.) Prowling on the Farnell I've encountered a PN7150 with 1.65V to 1.95V supply: https://www.newark.com/nxp/pn7150b0hn-c11002y/frequency-min/dp/06AC2460?st=pn7150 - it is not an actual supply but it applies to VDD and it is just an output which should be connected to VDDA and VDDD, am I right?
5.) I'm expecting a 0x28 address to be found.
Thank you for a quick reply. I already use 2.2k pull-ups for I2C bus. Also noticed there is about 1ms delay needed before driving Enable high. I've added a simple passive RC circuit (1k + 1uF) to delay it for about 3ms. Still no success. Now I'm waiting for a shipment to come with brand new PN7150s. If replacing it would not help I'll post more precise design data.
HI Marcin Pawelec
Does your PN7150s can be detected?
I also has same question. And the connection between PN7150 and host just same as your's.
Dose the wire connection need to modify?
I'm not sure if you fried your devices, I believe you will find these guides helpful.
https://www.nxp.com/docs/en/user-guide/UM10936.pdf - You can check here the timings needs
https://www.nxp.com/docs/en/application-note/AN11756.pdf - Here some of the Hardware needs
Also , you are mentioning that you are wiring the devices, are you considering the pull-up resistor needed for the I2C to work correctly?
Hope it helps