How much does it cost to build Aura AQ?
Choose the display, the main sensor and only the extra measurements you need. Here is what the parts cost, and what still needs to go into your budget.
The starting budget
A 4.3-inch Aura AQ display, SEN66 sensor and sensor cable come to US$95.97 before sales tax and tariffs. A 7-inch build is US$99.97 for those same three items. Add the assembled Aura PCB, enclosure, power supply and the remaining costs below.
- 4.3-inch
- US$95.97
- 7-inch
- US$99.97
Display + SEN66 + cable
Before sales tax and tariffs.- 4.3-inch
- €100.89
- 7-inch
- €105.15
Display + SEN66 + cable
Sensors include 19% VAT; display includes a VAT allowance.- 4.3-inch
- £86.93
- 7-inch
- £90.56
Display + SEN66 + cable
Sensors include 20% VAT; display includes a VAT allowance.These are priced-parts subtotals, not a complete build price.
Budget around US$90.00 for two assembled PCBs from PCBWay, before delivery. That allocates about US$45.00 to one build, but you pay for both boards when ordering alone. A local seller is another option if you need just one board. PCB shipping, import charges, other supplier delivery costs, enclosure, power, fixings and file access are separate.
For a first home build, the SEN66 gives you CO₂, particles, temperature, humidity and VOC/NOx indexes. Start with those if your questions are about ventilation, cooking, dust or everyday changes in room air. Add another sensor when you can name the question it will answer.
Which parts do you need?
Choose one display. Both listed boards are the 800 × 480 touchscreen versions with 16 MB flash. An 8 MB board or a similarly named B/C variant is not a substitute for this build.
Swipe or scroll the table sideways to compare all three markets.
| Part | USA · USD | Germany · EUR | UK · GBP |
|---|---|---|---|
| 4.3″ Waveshare touchscreenESP32-S3-Touch-LCD-4.3 · SKU 25948 | US$32.99 | €35.09 | £29.99 |
| 7″ Waveshare touchscreenESP32-S3-Touch-LCD-7 · SKU 27078 | US$36.99 | €39.35 | £33.62 |
| Sensirion SEN66One main air-quality sensor | US$62.03 | €64.81 | £56.08 |
| JST-GH sensor cable1.25 mm, 6 pins · Adafruit 5754 price reference | US$0.95 | €0.99 | £0.86 |
The cable is a separate item, but it does not need to be from Adafruit. The Adafruit 5754 price above is a reference; you can buy a JST-GH 1.25 mm, 6-pin cable from AliExpress or another supplier. My assembly instructions explain how to check the pinout and rearrange the contacts if needed before connecting it.
The rest of the core build needs an assembled Aura PCB, a printed enclosure with its specified fixings, and a stable 5 V / 2 A USB supply and cable. The assembled PCB includes the BMP388 pressure sensor and PCF8523 clock; check whether your supplier includes the CR1220 backup battery. A microSD card is an extra if you want local SD logging.
The interactive parts list (BOM) remains the wiring and connector reference. This guide adds prices and buying choices, including the newer Beta sensor options.
PCBWay or a local seller?
Use around US$90.00 as a starting budget for two assembled Aura PCBs, before shipping. Delivery can add a significant cost, so get a quote for your address before comparing suppliers. The final parts and assembly quote, taxes and import charges may also change the total.
As a batch-price reference, my April 2026 order for five assembled boards showed US$111.19, about US$22.24 per board. Delivery needs to be checked separately. A two-board order does not cost two-fifths of that amount: the fixed assembly charge stays much the same. The two-board figure here is a planning estimate based on that order, not a new PCBWay quote.
Allow around a month for PCBWay manufacturing, assembly and delivery. That is my planning allowance; the quoted production time and your shipping destination determine the actual wait.
- Estimated two-board order
- ≈ US$90.00 Two assembled PCBs; shipping extra
- Cost allocated to one board
- ≈ US$45.00 Half the board order; shipping extra
For a US 4.3-inch build, the three priced items plus the estimated whole PCB order come to about US$185.97, with a spare PCB left over. Allocating half of that PCB order to one build gives about US$140.97. Shipping, taxes and the other build expenses are extra.
For Germany and the UK, add the same US-dollar PCBWay estimate to the EUR or GBP subtotal. Keep it separate until checkout gives you the currency conversion, final shipping and any import charges. VAT and import fees are not assumed to be included in the estimate.
Choose the assembled PCB service. A low quote for bare circuit boards does not include the components or assembly.
Open the Aura PCBWay project ↗A local seller can be the more convenient choice for a single build. A board from local stock may cost a little more per unit than a share of a batch order, but you can buy just one and may receive it within a few days. You avoid the manufacturing wait; check stock and the delivery estimate for your address before ordering.
The parts list includes community sellers. For example, Manger Made listed one assembled Aura PCB at US$50 before tax and delivery when checked. Compare the delivered price of the quantity you actually need.
SEN66 or SEN69C?
Buy one, not both. SEN66 is the starting choice used in the budgets above. SEN69C is an alternative main module that also measures formaldehyde, called HCHO. It replaces SEN66 in that build.
SEN66 has the tighter CO₂ accuracy specification. At 1,000 parts per million (ppm), the typical accuracy figures in Sensirion’s datasheet, page 8 work out to ±75 ppm for SEN66 and ±200 ppm for SEN69C. These figures depend on the stated operating conditions, initial conditioning and automatic self-calibration, including weekly exposure to clean air near 400 ppm. SEN69C adds integrated formaldehyde measurement with this CO₂ trade-off.
Sensirion SEN69C-SIN-T
Beta 1.2.1Replacing SEN66 adds US$5.77 / €6.03 / £5.20. The connector cable is still required.
Choose it if a separate formaldehyde measurement is useful to your project and you accept the Beta firmware path. It does not identify every VOC or determine which material caused a reading. Sensirion lists the measured channels; the VOC/NOx guide explains why an index is a different type of result.
Aura uses SEN69C’s own HCHO channel and skips separate SFA30/SFA40 detection when SEN69C is present. Do not budget for an external HCHO module as well.
Check the Beta 1.2.1 release notes for SEN69C/SEN0321 support and remaining installation-test limitations. If upgrading an existing Aura, follow the model-specific 1.2.0 migration guide before moving from older firmware.
Which extra sensors are worth buying?
Extra channels serve particular jobs. A normal bedroom does not need the same sensors as a poultry house or a workshop using industrial gases. Check the expected concentration, required accuracy and operating conditions before adding a module.
The additional gas sensor guide explains the applications and limitations in detail. These modules add observations and history; Aura AQ does not replace certified CO alarms, workplace safety instruments or oxygen-deficiency protection.
CO · Carbon monoxide
SEN0466 · Optional channelConsider it for additional observations around a stove, fireplace or fuel-burning appliance. It is not an essential upgrade for every room and does not replace a certified CO alarm.
HCHO · SFA40 / DFRobot SEN0661
SEN66 builds onlyConsider it when formaldehyde is a specific measurement you want alongside SEN66. SEN0661 is the DFRobot module built around Sensirion SFA40. It was on backorder at the checked supplier.
Skip this addition if you choose SEN69C. A VOC index is not a formaldehyde concentration; the VOC/NOx article explains the distinction. See SEN0661 specifications and, for workshop context, the laser cutting and 3D printing article.
Already using SFA30?
The firmware also supports the older SFA30 path. As a price reference, the Seeed Grove formaldehyde module (101020972, based on SFA30) is listed below. It is a different breakout: check the wiring, connector and enclosure fit before substituting it. Buy only one external HCHO module.
Choose at most one specialised gas option
NH₃, H₂S, SO₂, NO₂, O₃ and O₂ share the specialised gas choice in Aura. The two ozone modules below are alternatives. Changing their connection addresses does not enable two simultaneous Aura gas channels.
Gas concentrations below use parts per million (ppm) or parts per billion (ppb): 1 ppm = 1,000 ppb. Resolution is the smallest reported step, so a 0.1 ppm step equals 100 ppb; it does not tell you how close a reading is to the true concentration.
NH₃ · Ammonia
SEN0469Consider it for a defined source, such as animal bedding, composting or an ammonia process.
Usually unnecessary for a bedroom or office. Its 1 ppm resolution is not a guarantee of accuracy; dust, moisture and other gases also matter.
H₂S · Hydrogen sulphide
SEN0467Consider it for additional observations around wastewater, manure handling or a biogas process.
A faint smell may require a more sensitive instrument. This is not a biogas analyser or equipment for entering a confined space.
SO₂ · Sulphur dioxide
SEN0470Consider it when a known process releases SO₂, for example winemaking or some industrial operations.
Check it against a suitable reference instrument before relying on trends. A published SEN04xx study found that its SO₂ channel did not follow the reference trend. It does not measure SO₂ in wine.
NO₂ · Nitrogen dioxide
SEN0471Consider it for additional observations around combustion equipment or engine exhaust, with a suitable reference check.
Its 0.1 ppm step is 100 ppb. Do not buy it on the assumption that it can accurately resolve small background pollution changes near a road. The SEN66 NOx index is a different measurement.
O₃ · Ozone, 10 ppb resolution
SEN0321 · Beta 1.2.1Consider it for a specific ozone-monitoring project after checking the concentrations and accuracy you need.
DFRobot specifies 0–10 ppm and 0.01 ppm (10 ppb) resolution. That finer step does not establish accurate outdoor background readings. Allow the manufacturer's 24–48 hours of initial conditioning.
O₃ · Ozone, 100 ppb resolution
SEN0472Consider it for additional observations around an ozone process when its range and sensitivity suit the task.
Its 0.1 ppm step is 100 ppb, so it is a poor choice for small outdoor ozone changes. It measures air, not dissolved ozone, and must not decide when a treated room is safe to enter.
O₂ · Oxygen
SEN0465Consider it for a project involving noticeable changes in oxygen percentage, such as a controlled storage atmosphere.
Skip it for ordinary room ventilation: CO₂ is the useful starting measurement there. This module does not replace an oxygen-deficiency alarm. When used with CO, set the O₂ module to the supported 0x75 address.
Resolution is not accuracy.
The SEN04xx specifications give a tolerance of ±10% of the reading or ±5% of full scale, whichever is greater. Small displayed steps do not promise equally small errors. A 2024 study of these modules found different performance across gases in its test setup, including a poor SO₂ trend match. Those findings do not establish universal errors or performance of SEN0321.
For both ozone options, a reading must not be used as clearance to re-enter a room after ozone treatment. Read the EPA explanation of ozone generators and their limitations.
0–10 V control · DFR0971 / GP8403
Optional output, not a sensorAdd this only if your ventilation or other equipment accepts a compatible 0–10 V control signal and you have planned the electrical interface. Skip it if you only want measurements, the local dashboard or Home Assistant data.
What else goes into the budget?
- Enclosure: use the chosen model’s slicer estimate for material and printing time, or get a printing-service quote. The larger screen needs its own enclosure.
- Files and access: check the current MakerWorld Builder Kit terms and what you already own. File access is not included in the hardware subtotal.
- Power and small parts: a suitable USB supply and cable, screws, inserts and other fixings from the assembly instructions. Check battery inclusion with the PCB supplier.
- Optional logging: a compatible microSD card if you want SD history. It is not included in the priced subtotal.
- Delivery and import costs: allow for separate supplier orders, taxes, tariffs and handling fees. Delivery is excluded from the PCBWay estimate too; check it separately for your address.
These costs depend on what you own, the enclosure you choose and where it ships. Leaving them out of a quoted “complete build” would hide part of the bill. Price them before ordering the electronics.
Use the parts configurator for your shopping checklist, then read where to place the finished monitor. For the main measurements, start with CO₂, particles and VOC/NOx indexes.
How these prices were checked
Prices were checked on 10 October 2026, for quantity one at each linked supplier. Every sensor price links to the exact regional DigiKey listing. US prices exclude sales tax and possible tariffs. German sensor prices include 19% VAT; UK sensor prices include 20% VAT. Delivery is separate. Availability can change; the quoted Adafruit cable and SEN0661 were on backorder at the check.
Waveshare’s own currency selector showed the 4.3-inch touchscreen at US$32.99 / €29.49 / £24.99 and the 7-inch at US$36.99 / €33.07 / £28.02. These are supplier quotes, not exchange rates calculated by Aura. The table adds a 19% German or 20% UK VAT allowance on the display price only: this is our budget calculation, not a tax-inclusive supplier quote. Shipping, any tax on shipping and other import charges remain outside it. See Waveshare’s duties and delivery terms.
The PCBWay amount is an approximate two-board budget informed by my April 2026 five-board order. Shipping is excluded and must be quoted separately; the historical order amount does not confirm its delivery cost. The estimate stays in USD for all three regions and is not a live checkout quote. The month-long PCBWay allowance and possible few-day local delivery are planning guides, subject to production, stock and shipping.
Waveshare and PCBWay links may support the project. The linked prices are reference offers from independent suppliers; availability, specification and final checkout costs should be checked before purchase.