For all the parts to this project, click here! Smart Doorbell System



The Smart Doorbell System is an idea for a wireless and portable bell-push/chime system with hopefully better range and features than expected from existing systems! It was a project developed in ten week(ends) and evenings.



For those that may wish to replicate the project (or parts of the project) then this blog post is a kind of 'supplement' with miscellaneous information such as the bill of materials (BoM) and links to any additional files or documents that could be useful.


Even if you're not interested in building it, hopefully some information here is useful - for example if you spot a part that you like in any of the blog posts, the order codes will be listed here.


Source Code

Bell Push Module and Chime Module

The source code is attached to this blog post in a file called To use it with TI Code Composer Studio, the BLE 5.0 stack version 1_50_00_71 needs to be installed (otherwise the code may need modification). The bell push module project is in the simple_central folder, and the chime module project is in the simple_peripheral folder. The code is very proof-of-concept, be prepared to modify it as needed. It is just a snapshot of code, and it will continue to be enhanced (it will probably be re-written).

Raspberry Pi Central and Peripheral Mode

The Pi can connect to the Bell Push and Chime Modules, in order to either tunnel events over the Internet, or to add new features like taking a photo from a Pi Camera whenever someone presses the Bell Push module, and so on. The source code for connecting to both modules is here: Smart Doorbell System - Part 9 - Working with BLE - What it is, and How to Use It!  . In that blog post, scroll to the section Creating a BLE Peripheral Device with a Raspberry Pi for the code that will receive Bell Push Module events. The section Creating a BLE Central Device with a Raspberry Pi contains the code that can connect to the Chime Module.

FM Music Synthesizer

The code that can be compiled and run on any Linux system (e.g. Pi) is available in this blog post: Smart Doorbell System – Part 8 – FM Sound Synthesizer and XDS110 Debugger and Tag-Connect Adaptor . For the code that runs on the CC2640R2, refer to the file mentioned earlier, called, in the simple_peripheral folder. The code is currently set to just produce a chime sound, but the FM synthesizer code is there too.


PCB Files

The PCB files for the Bell Push Module, the Chime Module, and the XDS110 to Tag-Connect Adaptor Board are all attached to this blog post.


Bill of Materials - Bell Push Module

Most of the components here like resistors and capacitors are interchangeable with other parts of the same value, in case some are out of stock. Any extra specific attributes that are important when selecting an alternative are listed in the Description field.


QtyValueMnfr CodeIdentifierFarnell CodeDescription
1-D2LS-21D2LS-21SW125232162523216D2LS series microswitch, Omron, surface mount
1-TACT-SW-9471898SW294718989471898TACT switch 9471898
1-TESTPOINT-1MMTP117020061702006Test Point terminal up to 1mm dia
10R0 ohm 0603R514697391469739Resistor 0603
2100R100 ohm 0402R2, R411741461174146Resistor 0402
1100k100kohm 0402R123028392302839Resistor 0402
122R22 ohm 0402R692390309239030Resistor 0402
1270R270 ohm 0402R323314972331497Resistor 0402
133R33 ohm 0402R792390579239057Resistor 0402
7100nC0402C104M3RACTUC0402C104M3RACTUC14, C15, C16, C17, C18, C19, C2025283422528342100nF 25V 0402 X7R Capacitor
210uZRB18AR61E106ME01LC13, C212469398246939810uF 25V 0603 X5R Capacitor
312pC0402C120G5GACTUC6, C10, C112821065282106512pF 0402 C0G Capacitor
31pGRM1555C1H1R0BA01DC1, C3, C5261189326118931pF 0402 C0G Capacitor
16.8pGJM1555C1H6R8BB01DC2278144027814406.8pF 0402 C0G Capacitor
11.8pCBR04C189B5GACCBR04C189B5GACC8261260726126071.8pF 0402 C0G Capacitor
11uC-EUC0603C12CAPACITOR, European symbol
3DNFC-EUC0402C4, C7, C9N/ACAPACITOR, European symbol
110uHLB2012T100KRL51463501146350110uH 120mA 0805 Inductor
22.4nHLQW15AN2N4B00DLQW15AN2N4B00DL1, L2247032824703282.4nH RF Inductor 0402 Murata
22nHL-07W2N0CV4TL-07W2N0CV4TL3, L4186582218658222nH RF Inductor 0402 Johanson
124MHzX1E0000210122 TSX-3225 24 MHZ 9.0PFX11712842171284224MHz crystal, TSX-3225 3.2x2.5mm
132.768kHzABS07-32.768KHZ-7-TX2183893518389353.2x1.5mm Xtal, example is Abracon ABS07 or ABS071 packages, e.g. Farnell 1838935 Abracon ABS07-32.768KHZ-7-T - Crystal, 32.768 kHz, SMD, 3.2mm x 1.5mm, 7 pF, 20 ppm, ABS07 Series
1AA+596B1+16507071650707Positive battery contact, Keystone
1AA-590B1-13398441339844Negative battery contact, Keystone
1CC2640R2FRGZCC2640R2FRGZU126902252690225CC2640R2FRGZ 48-pin QFN with pad package Texas Instruments
1ORANGEVLMO30L1M2-GS08VLMO30L1M2-GS08D113283321328332LED Vishay VLM_30 series Orange, 2 mA, 1.8 V
1U.FLU.FL-R-SMT-1(10)J216880771688077U.FL RF Connector


Bill of Materials: Chime Module

Chime module BoM:


QtyValueMnfr CodeIdentifierFarnell CodeDescription
2-M20-7831046M20-7831046A1, A27992025799202520-way DIL header socket
10R0 ohm 0603R1714697391469739Resistor 0603
2100R100 ohm 0603R23, R2414697521469752Resistor 0603
510k10k 0603R3, R6, R13, R15, R2517389181738918Resistor 0603
21k1k 0603R7, R914697401469740Resistor 0603
42.2k2.2k 0603R4, R5, R20, R2614697651469765Resistor 0603
1220R220R 0603R21Resistor 0603
122k22k 0603R19Resistor 0603
1270R270R 0603R22Resistor 0603
333R33R 0603R8, R12, R14Resistor 0603
239k39k 0603R10, R11Resistor 0603
14.7k4.7k 0603R16Resistor 0603
2470R470R 0603R1, R226144452614445Resistor 0603
147k47k 0603R18Resistor 0603
9100n100n 0603C2, C7, C11, C12, C14, C15, C19, C20, C2413017131301713Capacitor X7R 0603
110n10n 0603C2222806462280646Capacitor X7R 0603
110u10u 0805C325251452525145Capacitor X7R 0805
210uEEEHD1E100AREEEHD1E100ARC16, C1817147351714735Capacitor 10uF 25V Aluminium Panasonic 'C' size
11uC2012X7R1H105K125ABC17, C2123469442346944Capacitor X7R 0805
62.2uGRM21BR71A225KA01LC1, C5, C6, C9, C10, C13182892318289232.2uF 10V X7R 0805 Capacitor
22n22.2n C0G 0603C4, C8881994788199472.2nF 0603 C0G Capacitor
14.7uF 10VC2012X7R1A475K125ACC23234693623469364.7uF 10V X7R 0805 Capacitor
2FBEADIND-0805L1, L2
1TLV431TLV431AIDBZRD121443152144315TLV431 Adjustable Shunt Reg. Texas Instruments
1ORANGEVLMO30L1M2-GS08VLMO30L1M2-GS08D413283321328332LED Vishay VLM_30 series Orange, 2 mA, 1.8 V
2BC847BC847Q1, Q2
1PCM5101APCM5101AU124022502402250PCM5101APWR DAC TI TSSOP20
1TPA6211A1TPA6211A1U227828602782860TPA6211A1 TI Audio Power Amplifier3.1 W MSOP
1LM1117-5.0LM1117IMP-5.0U3232358123235815V LM1117IMP-5.0  800mA Linear Regulator
1LTC4411LTC4411ES5#TRMPBFU4LTC4411 2.6A Low Loss Ideal Diode
2REG101NA-3.3REG101U5, U6170339717033973.3V REG101 fixed voltage regulator, SOT23-5 package
2-DTSM-32S-BDTSM-32S-BSW1, SW294718989471898TACT switch Multicomp  DTSM-32S-BDTSM-32S-B
1-695402400222J326644332664433WR-LECO connector Wurth
1-DCJACKJ1DC Jack 2.1mm inner pin
1-JST-PH-2J22-pin connector (JST PH series)
1-TESTPOINT-1MMTP117020061702006Test Point terminal up to 1mm dia




Soldering: Useful Tools


1Mini FridgeThe cheap 12V travel mini-fridges (e.g. from Argos or CPC in the UK) last for years – although the mains brick barely lasts more than a year! – so I purchased a separate high quality mains brick from Farnell
2SolderI used Qualitek 818 which is no-clean solder paste Sn62/Pb36/Ag2. Wash your hands afterwards!
3Cleaning stuffI used Qualitek stencil wipes and Isopropyl alcohol from MG Chemicals, and Dettol : ) for general cleaning
4Flat work surfaceAluminium or plastic slab
5Sticky tapeAny tape, for working with the stencil
6Kapton tapeIdeal for attaching thermocouple probes
7SpatulaFor handling the solder paste
8Low cost stainless steel tweezersFor general work near the heated board
9Good quality tweezersFor handling the surface mount components
10ThermometerFor using in the 'fridge, or for monitoring room temperature
11SqueegeeTransition Automation handheld squeegee, available from Somerset Solders in the UK
12Hot Air PenI used a Metcal  HCT2-120HCT2-120 but the HCT2-200 is newerHCT2-200 is newer
13Pre-HeaterThermaltronics TMT-PH200 from AMS Electronics in the UK
14Camera, Microscope or LensI use various ones as required
15Light/LampA good light source helps : )