User's Manual

Table Of Contents
BL652
Datasheet
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Optional External Serial (SPI) Flash
This is not required for normal BL652 module opertion.
If you fit an optional external serial (SPI) flash (such as for data logging purpose) then that external serial (SPI)
flash must connect to BL652 module pins SIO_12 (SFLASH_CS), SIO_14 (SFLASH_MISO), SIO_16 (SFLASH_CLK),
and SIO_20 (SFLASH_MOSI); in that case a high level API in smartBASIC can be used for fast access using
open/close /read/write API functions.
Note: By default, these are GPIO pins. Only when in their FlashOpen()smartBASIC app are these lines
dedicated to SPI and for talking to the off-module board SPI flash.
If you decide to use external serial (SPI) flash with the BL652-SX-xx, then ONLY the manufacturer part numbers
below MUST be used:
4-Mbit Macronix MX25R4035F
http://www.macronix.com/Lists/DataSheet/Attachments/3288/MX25R4035F,%20Wide%20Range,%204Mb,
%20v1.2.pdf
8-Mbit Macronix MX25R8035F
http://www.macronix.com/Lists/DataSheet/Attachments/3532/MX25R8035F,%20Wide%20Range,%208Mb,
%20v1.2.pdf
For any external serial (SPI) flash other than these part numbers, smartBASIC does not provide access.
Optional External 32.768 kHz crystal
This is not required for normal BL652 module operation.
The BL652 uses the on-chip 32.76 kHz RC oscillator (LFCLK) by default (which has an accuracy of ±250 ppm) which
requires regulator calibration (every eight seconds) to within ±250 ppm.
You can connect an optional external high accuracy (±20 ppm) 32.768 kHz crystal to the BL652-SX-xx pins,
SIO_01/XL2 (pin 24) and SIO_00/XL1 (pin 25) to provide improved protocol timing and to help with radio power
consumption in the system standby doze/deep sleep modes by reducing the time that the RX window needs to
be open. Table 26 compares the current consumption difference between RC and crystal oscillator.
Table 26: Comparing current consumption difference between BL652 on-chip RC 32.76 kHz oscillator and optional external crystal
(32.768kHz) based oscillator
BL652 On-chip 32.768 kHz RC Oscillator
(±250 ppm) LFRC
Optional External Higher Accuracy (±20 ppm)
32.768 kHz Crystal-based Oscillator XO
Current
Consumption
of 32.768 kHz
Block
0.6 uA
0.25 uA
Standby Doze
Current
1.2 uA
1.2 uA