Hi!
Foreword: I'm just approaching programmability of XBee3 modules, I don't own any S2C modules - so I might be totally wrong.
From Adafruit, manufacturer of your LCD module, we know ST7565 display has to be driven through Serial Peripheral Interface (http://www.ladyada.net/learn/lcd/st7565.html).
And Digi's "XBee/XBee-PRO S2C Zigbee® RF Module" guide shows us the internal programmable connections for S2C modules, here:
https://www.digi.com/resources/documentation/digidocs/90002002/default.htm#Reference/r_programmable_connections.htm%3FTocPath%3DProgrammable%2520XBee%2520SDK%7C_____1
Please have a look at these internal schemas. Since you are using XB24CZ7UISB003, a SMT version of XBee, let's focus only on first picture. PDF version of the same guide (here, https://www.digi.com/resources/documentation/digidocs/pdfs/90002002.pdf) has better resolution, so open it at page 36. Here you'll find two interesting ICs
- NXP's (formerly Freescale) MC9S08QE32CFT - a.k.a. HCS08, a MicroController Unit packaged as QFN-48 (data-sheets here https://www.nxp.com/docs/en/reference-manual/MC9S08QE32RM.pdf),
- and Silicon Labs's (formerly Ember) EM357, the System-on-Chip ZigBee Network Co-Processor, basic IC for XBee modules, QFN-48 too (https://www.silabs.com/documents/public/data-sheets/EM35x.pdf).
The same schema shows you that pins #
- 44,
- 43,
- 42,
- 41
of HCS08 (port E, bits from 0 to 3) are respectively mapped to
- Serial Clock
- Master Data Out, Slave Data In,
- Master Data In, Slave Data Out,
- Slave Select (active low)
of SPI module internal to MCU (please note this position is NOT the default mapping, according to data-sheets).
Those are also respectively connected to pins #
- 14 (SPI_SCLK / DIO18),
- 16 (SPI_MOSI / DIO16),
- 17 (SPI_MISO / DIO15),
- 15 (nSPI_SSEL / DIO17)
of your XBee S2C SMT module.
Knowing this, you could try to drive the display just by properly connecting it to pins 14 to 17 of your XB24CZ7UISB003... provided Digi's SDK for S2C programmable modules (which, again, I don't know) lets you access the SPI module of HCS08.
Unfortunately this can't be taken for granted: in my short experience with XBee3 ZigBee modules, I can tell you MicroPython implementation (which will supplant Digi's SDK for programming more recent modules, I presume) still lacks lot of useful modules/functions (not just serial interfaces... even basic I/O control!).
For the sake of information, external pins #:
- 14,
- 16,
- 17,
- 15
of your XBee S2C SMT module are probably connected to internal EM357's pins #:
- 19 (PB3),
- 30 (PB1, or pin #31 - PB2 - if configured as slave),
- 31 (PB2, or pin #30 - PB1 - if configured as slave),
- 20 (PB4)
if Serial Controller 1 is used. Otherwise they should be connected to pins #:
- 24 (PA2),
- 21 (PA0),
- 22 (PA1),
- 25 (PA3)
if Serial Controller 2 is used.
Good luck with your project!