nRF52840 Product Specification V1.7 (Revision History) November 2021

Hi there,
Any qualified SEEED Personnel willing to comment on this being the current revision the Xiao is sporting? Are we Using the aQFN73 package under the Lid?
are these the current spec’s according to Section 9?, I’m somewhat confident in the information from Nordic Semi. Need some idea from SEEED Eng.

9 Absolute maximum ratings
Maximum ratings are the extreme limits to which the chip can be exposed for a limited 
amount of time without permanently damaging it. Exposure to absolute maximum ratings for prolonged periods of time may affect the reliability of the device.

along with the Feature List.

• Bluetooth ® 5, IEEE 802.15.4-2006, 2.4 GHz transceiver
• -95 dBm sensitivity in 1 Mbps Bluetooth ® low energy mode
-103 dBm sensitivity in 125 kbps Bluetooth ® low energy mode (long range)
• -20 to +8 dBm TX power, configurable in 4 dB steps
• On-air compatible with nRF52, nRF51, nRF24L, and nRF24AP Series
• Supported data rates:
• Bluetooth ® 5 – 2 Mbps, 1 Mbps, 500 kbps, and 125 kbps
• IEEE 802.15.4-2006 – 250 kbps
• Proprietary 2.4 GHz – 2 Mbps, 1 Mbps
• Single-ended antenna output (on-chip balun)
• 128-bit AES/ECB/CCM/AAR co-processor (on-the-fly packet encryption)
• 4.8 mA peak current in TX (0 dBm)
• 4.6 mA peak current in RX
• RSSI (1 dB resolution)
• ARM ® Cortex ® -M4 32-bit processor with FPU, 64 MHz
• 212 EEMBC CoreMark ® score running from flash memory
• 52 µA/MHz running CoreMark from flash memory
• Watchpoint and trace debug modules (DWT, ETM, and ITM)
• Serial wire debug (SWD)
• Rich set of security features
• ARM ® TrustZone ® Cryptocell 310 security subsystem
• NIST SP800-90A and SP800-90B compliant random number generator
• Chacha20/Poly1305 AEAD supporting 128- and 256-bit key size
• SHA-1, SHA-2 up to 256 bits
• Keyed-hash message authentication code (HMAC)
• RSA up to 2048-bit key size
• SRP up to 3072-bit key size
• ECC support for most used curves, including P-256 (secp256r1) and Ed25519/Curve25519
• Application key management using derived key model
• Secure boot ready
• Flash access control list (ACL)
• Root-of-trust (RoT)
• Debug control and configuration
• Access port protection (CTRL-AP)
• Secure erase
• Flexible power management
• 1.7 V to 5.5 V supply voltage range
• On-chip DC/DC and LDO regulators with automated low current modes
• 1.8 V to 3.3 V regulated supply for external components
• Automated peripheral power management
• Fast wake-up using 64 MHz internal oscillator
• 0.4 µA at 3 V in System OFF mode, no RAM retention
1.5 µA at 3 V in System ON mode, no RAM retention, wake on RTC
• 1 MB flash and 256 kB RAM
• Advanced on-chip interfaces
• USB 2.0 full speed (12 Mbps) controller
• QSPI 32 MHz interface
• High-speed 32 MHz SPI
• Type 2 near field communication (NFC-A) tag with wake-on field
• Touch-to-pair support
• Programmable peripheral interconnect (PPI)
• 48 general purpose I/O pins
• EasyDMA automated data transfer between memory andperipherals
Nordic SoftDevice ready with support for concurrent multiprotocol
• 12-bit, 200 ksps ADC – 8 configurable channels with programmable gain
• 64 level comparator
• 15 level low-power comparator with wake-up from System OFF mode
• Temperature sensor
• 4x four channel pulse width modulator (PWM) unit with EasyDMA
• Audio peripherals – I2 S, digital microphone interface (PDM)
• 5x 32-bit timer with counter mode
• Up to 4x SPI master/3x SPI slave with EasyDMA
• Up to 2x I2 C compatible two-wire master/slave
• 2x UART (CTS/RTS) with EasyDMA
• Quadrature decoder (QDEC)
3x real-time counter (RTC)
• Single crystal operation
• Package variants
• aQFN™ 73 package, 7 x 7 mm
• QFN48 package, 6 x 6 mm
• WLCSP package, 3.544 x 3.607 mm <----- "Or is it this package"
I am particularly interested in the bolds,
I ask because the package may lead to what is available and supported.
GL :slight_smile: PJ

:wink: just got three(3) more…

-103 dBm sensitivity in 125 kbps Bluetooth ® low energy mode (long range)

I’m interested in this.
I would be interesting if it could be easily used on an Arduino.

Hi there, msfujino
I would too, Allot is only accessible from SDK ESP IDF so it seems, all the extra GATT stuff isn’t in the BLE arduino LIB’s and idunno how much is in the softdevice too?
Nordic has 8 concurrent connections of peripherals to one central Blinky example with dev board kit, (would be a very attractive SEEED demo btw) and Up to 20 in a round robin state machine method. and to get full transmit power +8dbm I don’t think its truely supported even in adafruit , because of the coded PHY stuff? (above my level) they use Zephyr RTOS lower level.
I hope someone in the engineering dept. could speak on some of this and comment on any support.
I play the powerball too so. :v:
GL :slight_smile: PJ

Have you seen the specs on this product , How do they do it? LOL

GL :slight_smile: PJ
:speaking_head:beacon on steroids :mechanical_arm:

Adafruit has not implemented this feature, some discussion here:
Long Range Support
You can see from above vladkozlov69 has done some work but not sure how it works.
Practically speaking, although lower bit rate improves the sensitivity, the packets are more prone to interference due to increased on-air time. So the range improvement depends on whether the environment is noisy or not.

1 Like

Testing Long Range (Coded PHY) with Nordic solution (It Simply Works) - Blogs - Nordic Blog - Nordic DevZone
I am very interested in codedPHY after reading this article. I have looked up a lot of information but it is quite difficult for me.
I think I will wait until it works with Aruduino.

1 Like

I’m with you, Seems LONG RANGe and Multiple concurrent connections(8) are two slices missing from the Arduino BLE Pie :slight_smile:
interesting part of it is the position;

from the link…

Holding your test kits in the correct position/direction

The picture below shows the front side of the DK, where you can see the Nordic chip (nRF52840), the matching network (marked with a red box), and the connector for the external antenna. We are not using an external antenna, and just using the PCB antenna that is printed on board. So with this specific PDK, the radio pattern radiates strongest on the front side. It radiates on the backside of the PDK as well, but you will observe a radio signal strength loss of about 3-4 dBm on the backside. This is due to many reasons (material of PDK, underlying printed metal circuit, etc). Therefore, it is best that when you are testing with PDKs, you set them facing each other as shown below. They do not need to be aligned to the same altitude. Facing them each other with any individual altitude should be ok.


GL :slight_smile: PJ

I’m liking this article here,

# Bluetooth 5 : Long Range + Advertising Extension on NRF52840

GL :slight_smile: PJ

Long Range is the hottest topic in my mind right now.

You see this stuff by jimmie wong?

it’s with the nRF sdk but good info and code insite…
GL :slight_smile: PJ

This is the secret sauce IMO

Fig 4. BLE coding and modulation schemes

For 1Mbs and 2Mbs this remains the case, however for the longer range options (LE coded) of 
500kbs and 125kbs, this changes. As can be seen in fig 4. The payloads have multiple symbols
 for each bit, S = 2 for 500kbs and S = 8 for 125kbs (where S is the symbol/bit rate), this in 
essence means more symbols per bit allows more tolerance with a poor signal to noise ratio, 
and still provide a recoverable data stream. In short this allows a receiver to correct bit errors 
on the receiving side of a communication link.

This process happens entirely in hardware and is transparent to the developer.
 The required data rate is chosen and packets arrive and are delivered by the 
SoftDevice to the application in the same way regardless of on-air data rate.
 Fig 5 shows the system blocks for data processing for uncoded and coded 
PHY on the TX and RX sides.

Good basic short video of Coded PHY and the more power required because transmitter is on long to sen dat at lower 125k rate.

PJ, thanks for the info.
My head overflow with information
so I read slowly.

Welcome aboard… I read real,real slow… :smiley:
But here is a GREAT thread with a happy ending,
How a company had in it’s Literature "LONG RANGE BLE supported" One very talented fellow realized it was more marketing than FACT. He needed it for his own DEVICE, He was able to help them add the support to their product for everyone to use.
He got a Grant from the “National Academy of Medicine” his product is pictured.
BLE 5 Long Range (Coded Phy, 125 kbps) mode. How to engage?

Some companies would benefit heeding this story, Just saying :lying_face:
GL :slight_smile: PJ


spoiler alert They are using this chip.Laird PN 451-00001

Very Robust for Roll your own PCB’s… With CODED PHY 125KB Long Range :wink: :pray: